阅读说明：本技术 低二聚化紫精电致变色化合物和器件 (Low dimerization viologen electrochromic compounds and devices ) 是由 L·J·克勒普纳 Z·B·艾尔诺 H·A·鲁特恩 于 2020-04-07 设计创作，主要内容包括：提供了一种用于电致变色介质和包括所述电致变色介质的电光元件中的低二聚化电致变色化合物。所述低二聚化电致变色化合物由式(I)表示：其中每一个R-(1)单独地为烷基、羟烷基或被至少一个可聚合官能团所取代的烷基；每一个R-(2)为氢；每一个R-(3)单独地为氢或烷基；并且每一个R-(4)单独地为氢、烷基或羟烷基；并且X～(-)为阴离子。(A low-dimerization electrochromic compound for use in electrochromic media and electro-optic elements including the electrochromic media is provided. The low dimerization electrochromic compound is represented by formula (I): wherein each R 1 Independently of alkyl, hydroxyalkyl or substituted by at least one polymerizable functional groupAn alkyl group; each R 2 Is hydrogen; each R 3 Independently hydrogen or alkyl; and each R 4 Independently hydrogen, alkyl or hydroxyalkyl; and X ‑ Is an anion.)

1. An electro-optic element, comprising:

a hypodimerizing electrochromic compound of formula (I):

wherein:

each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group;

each R₂Is hydrogen;

each R₃Independently hydrogen or alkyl;

each R₄Independently hydrogen, alkyl or hydroxyalkyl; and is

X^-Is an anion.

2. The electro-optic element of claim 1, wherein the polymerizable functional group is selected from at least one of a vinyl group, an acrylate group, a methacrylate group, a vinyl ether group, a hydroxyl group, an isocyanate group, an oxetane group, and an epoxy group.

3. The electro-optic element of claim 1 or claim 2, wherein at least one R₄Is a methyl group.

4. The electro-optic element of any of claims 1-3, wherein at least one R₁Comprising a polymerizable functional group.

5. The electro-optic element of any of claims 1-4, wherein the electrochromic compound of formula (I) is one of dissolved in a solvent, incorporated into a gel, or incorporated into a polymer film.

6. The electro-optic element of claim 5, wherein the electrochromic compound of formula (I) is at least one of incorporated into a backbone of polymeric chains forming the polymeric film or covalently bonded as a pendant group to the polymeric chains of the polymeric film.

7. The electro-optic element of any of claims 1-6, wherein X^-Is selected from F^-、Cl^-、Br^-、I^-、BF₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、ClO₄ ^-、SO₃CF₃ ^-、N(CN)₂ ^-、C(CF₃SO₂)₃ ^-、N(SO₂C₂F₅)₂ ^-、N(CF₃SO₂)₂ ^-And Al (OC (CF)₃)₃)₄ ^-At least one of (a).

8. The electro-optic element of any of claims 1-7, further comprising:

an electrochromic medium comprising the electrochromic compound of formula (I); and

a chamber defined at least in part by a first conductive layer of a first substrate, a second conductive layer of a second substrate, and a sealing member joining the first substrate and the second substrate,

wherein the electrochromic medium is disposed within the chamber.

9. An electrochromic medium for use in an electro-optic element, the electrochromic medium comprising:

a hypodimerizing electrochromic compound of formula (I):

wherein:

each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group;

each R₂Is hydrogen;

each R₃Independently hydrogen or alkyl;

each R₄Independently hydrogen, alkyl or hydroxyalkyl; and is

X^-Is an anion.

10. The electrochromic medium of claim 9, wherein the polymerizable functional group is selected from at least one of a vinyl group, an acrylate group, a methacrylate group, a vinyl ether group, a hydroxyl group, an isocyanate group, an oxetane group, and an epoxy group.

11. The electrochromic medium of claim 9 or claim 10, wherein each R is₄Is a methyl group.

12. The electrochromic medium of any one of claims 9-11, wherein at least one R₁Comprising a polymerizable functional group.

13. The electrochromic medium of any one of claims 9-12, wherein the electrochromic compound of formula (I) is one of dissolved in a solvent, incorporated into a gel, or incorporated into a polymer film.

14. The electrochromic medium of any one of claims 9-13, wherein X^-Is selected from F^-、Cl^-、Br^-、I^-、BF₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、ClO₄ ^-、SO₃CF₃ ^-、N(CN)₂ ^-、C(CF₃SO₂)₃ ^-、N(SO₂C₂F₅)₂ ^-、N(CF₃SO₂)₂ ^-And Al (OC (CF)₃)₃)₄ ^-At least one of (a).

15. An electro-optic element, comprising:

a hypodimerizing electrochromic compound of formula (II):

wherein:

each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group;

each R₂Is hydrogen;

each one of which isR₄Independently hydrogen, alkyl or hydroxyalkyl;

each R'₄Independently hydrogen, alkyl or hydroxyalkyl; and is

X^-Is an anion.

16. The electro-optic element of claim 15, wherein the polymerizable functional group is selected from at least one of a vinyl group, an acrylate group, a methacrylate group, a vinyl ether group, a hydroxyl group, an isocyanate group, an oxetane group, and an epoxy group.

17. The electro-optic element of claim 15 or claim 16, wherein at least one R₄Or at least one R'₄Is a methyl group.

18. The electro-optic element of any of claims 15-17, wherein at least one R₁Comprising a polymerizable functional group.

19. The electro-optic element of any of claims 15-18, wherein the electrochromic compound of formula (II) is one of dissolved in a solvent, incorporated into a gel, or incorporated into a polymer film.

20. The electro-optic element of any of claims 15-19, wherein X^-Is selected from F^-、Cl^-、Br^-、I^-、BF₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、ClO₄ ^-、SO₃CF₃ ^-、N(CN)₂ ^-、C(CF₃SO₂)₃ ^-、N(SO₂C₂F₅)₂ ^-、N(CF₃SO₂)₂ ^-And Al (OC (CF)₃)₃)₄ ^-At least one of (a).

Technical Field

The present disclosure relates generally to electrochromic compounds for electro-optic elements and media, and more particularly to low-dimerization viologen-based electrochromic compounds.

Disclosure of Invention

According to one aspect of the present disclosure, an electro-optical element comprises a low-dimerization electrochromic compound of formula (I):

wherein each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group; each R₂Is hydrogen; each R₃Independently hydrogen or alkyl; each R₄Independently hydrogen, alkyl or hydroxyalkyl; and X^-Is an anion.

According to one aspect of the present disclosure, an electrochromic medium for use in an electro-optical element comprises a low-dimerization electrochromic compound of formula (I):

wherein each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group; each R₂Is hydrogen; each R₃Independently hydrogen or alkyl; each R₄Independently hydrogen, alkyl or hydroxyalkyl; and X^-Is an anion.

According to one aspect of the disclosure, an electro-optical element comprises a low-dimerization electrochromic compound of formula (II):

wherein each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group; each R₂Is hydrogen; each R₄Independently hydrogen, alkyl or hydroxyalkyl; each R'₄Independently hydrogen, alkyl or hydroxyalkyl; and X^-Is an anion.

According to one aspect of the present disclosure, an electrochromic medium for use in an electro-optical element comprises a low-dimerization electrochromic compound of formula (II):

wherein each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group; each R₂Is hydrogen; each R₄Independently hydrogen, alkyl or hydroxyalkyl; each R'₄Independently hydrogen, alkyl or hydroxyalkyl; and X^-Is an anion.

These and other features, advantages, and objects of the present disclosure will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.

Drawings

In the drawings:

fig. 1 is a cross-sectional illustration of an electrochromic device according to one aspect of the present disclosure;

fig. 2A is a cross-sectional view of an electro-optic element according to one aspect of the present disclosure;

fig. 2B is a cross-sectional view of an electro-optic element according to one aspect of the present disclosure;

fig. 2C is a cross-sectional view of an electro-optic element according to one aspect of the present disclosure;

fig. 2D is a cross-sectional view of an electro-optic element according to one aspect of the present disclosure;

fig. 2E is a cross-sectional view of an electro-optic element according to one aspect of the present disclosure;

FIG. 3 illustrates the chemical structure of an exemplary electrochromic compound-example compound (I), according to one aspect of the present disclosure; and

fig. 4 is a flow diagram depicting a synthesis scheme for synthesizing exemplary electrochromic compounds, according to one aspect of the present disclosure.

Detailed Description

The embodiments illustrated herein reside primarily in combinations of materials, method steps, and apparatus components related to a low-dimerization viologen-based compound for use in electrochromic media and related devices. Accordingly, the apparatus components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Further, like numerals in the description and drawings represent like elements.

As used herein, the term "and/or," when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B and/or C, the composition may contain: only A; only B; only C; a combination of A and B; a combination of A and C; a combination of B and C; or a combination of A, B and C.

For purposes of description herein, the terms "upper," "lower," "right," "left," "rear," "front," "vertical," "horizontal," and derivatives thereof shall all be oriented as in fig. 1 in connection with the present disclosure. Unless otherwise specified, the term "front" shall refer to the surface of the device that is closer to the intended viewer of the device, while the term "rear" shall refer to the surface of the device that is farther from the intended viewer of the device. It is to be understood, however, that the present disclosure may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.

In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further restriction, an element that is preceded by "comprising … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Aspects of the present disclosure relate to a family of electrochromic compounds capable of attenuating transmittance of at least a portion of the electromagnetic spectrum. The electrochromic compounds of the present disclosure are useful in electro-optic elements and electrochromic devices including such electro-optic elements. Electrochromic compounds of the present disclosure include a hypodimerized viologen-based compound of formula (I):

wherein each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group; each R₂Is hydrogen; each R₃Independently hydrogen or alkyl; each R₄Independently hydrogen, alkyl or hydroxyalkyl; and X^-Is an anion. The compounds of formula (I) typically include a 3, 3' ethylene bridge wherein each R is₄May be hydrogen, alkyl or hydroxyalkyl.

According to another aspect of the disclosure, the electrochromic compound comprises a hypo-dimeric viologen-based compound of formula (II):

wherein each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group; each R₂Is hydrogen; each R₄Independently hydrogen, alkyl or hydroxyalkyl; each R'₄Independently hydrogen, alkyl or hydroxyalkyl; and X^-Is an anion. The compounds of formula (II) are similar to the compounds of formula (I) except that the compounds of formula (II) further comprise a 5,5' ethylene bridge wherein each R is₄And R'₄May be hydrogen, alkyl or hydroxyalkyl.

Viologen-based electrochromic compounds of formulae (I) and (II) can be used as cathode materials in combination with anode materials to form electro-optic elements that can be incorporated into electrochromic devices. The viologen-based electrochromic compounds of formulae (I) and (II) of the present disclosure can be characterized by low dimer formation when used in electro-optic elements and electrochromic devices. By way of introduction, conventional electrochromic devices may comprise a conventional viologen, such as di-n-octyl viologen bis (tetrafluoroborate) (also known as octyl viologen), and a conventional anode material, such as 5, 10-dihydro-5, 10-Dimethylphenazine (DMP). In operation, conventional electrochromic devices may exhibit a color change when the conventional viologen compound octyl viologen undergoes an electron reduction that results in an increase in the absorbance of light in the visible region of the electromagnetic spectrum. For example, octyl viologen in Propylene Carbonate (PC) solvent will exhibit a λ -max at about 605nm upon undergoing one electron reduction and thus become blue in appearance. However, a second rate of absorption is also observed when octyl viologen undergoes one electron reduction, which is theoretically the result of dimerization of two single electron reduced viologen monocationic radicals. This second absorptance can be blue-shifted from the single cation radical absorptance, where the cation radical dimer exhibits a λ -max of about 520 nm. The additional absorption exhibited by the viologen radical cation dimers can lead to a change in the appearance of the electrochromic device, which may be undesirable.

Formation of viologen dimers is generally a reversible process characterized by a dimer formation reaction rate (forward reaction rate) and a monocationic radical formation reaction rate (reverse reaction rate), and thus the color change due to dimer formation is also a reversible process. The forward and reverse reaction rates of the dimer may be affected by a variety of factors, such as temperature and cationic radical concentration. Since color change is affected by the forward and reverse reaction rates of the dimer, these factors also affect color change. For example, the temperature environment within which the electrochromic device is used may result in an increase in the rate of dimer forward reaction (rate of dimer formation) compared to other end use environments, and thus, color change due to dimer formation is a greater challenge for some devices than others. When used in electro-optic elements, the viologen-based compounds of formulae (I) and (II) according to the present disclosure may exhibit reduced or low dimerization characteristics. The viologen-based compounds of the present disclosure can reduce or eliminate the color change that some conventional electrochromic devices may undergo due to dimerization of viologen-based cationic radicals.

Referring to fig. 1 and 2A-E, reference numeral 10 generally designates an electrochromic device according to one aspect of the present disclosure. The electrochromic device 10 may include a first substrate 70 having a first surface 74 and a second surface 78 and a first conductive layer 82 disposed on the second surface 78. The second substrate 86 is disposed opposite the first substrate 70 and includes a third surface 90 and a fourth surface 94. A second conductive layer 98 is disposed on the third surface 90. The first and second substrates 70, 86, along with the sealing member 106, define a chamber 110 for containing an electrochromic medium. The electrochromic device 10 may further include one or more plugs 130 associated with one or more fill ports. The one or more fill ports may be disposed within the first substrate 70, the second substrate 86, or the sealing component 106. When mounted as a mirror, window, filter, or other device, the electrochromic device 10 may optionally include a bezel (not shown) that extends around the periphery of at least one of the first substrate 70 and/or the second substrate 86 to conceal and/or protect components of the electrochromic device 10, etc., such as bus connectors (if present), the sealing member 106, one or more plugs 130, and/or one or more fill ports.

In some aspects, the first substrate 70 or the second substrate 86 may be larger in size than each other or the same, but moved to create an offset along at least a portion of the perimeter of the electrochromic device 10 to allow easier access to the first and/or second conductive layers 82, 98. First substrate 70 and/or second substrate 86 may be made of glass, plastic, or other optically transparent or translucent materials, non-limiting examples of which include borosilicate glass, soda lime glass, or polymeric materials such as natural and synthetic polymeric resins, plastics, and/or composites including polyesters (e.g., PET), Polyimides (PI), polycarbonates, polysulfones, polyethylene naphthalate (PEN), Ethylene Vinyl Acetate (EVA), acrylate polymers, and polymers that may be made from polyethylene naphthalate (PEN), polyethylene naphthalate (EVA), and/or polyethylene naphthalate (pe), and/or other polymers, and/or copolymers, and combinations thereofCyclic Olefin Copolymers (COC) commercially available from Advanced Polymers. In some aspects, both the first substrate 70 and the second substrate 86 are made of an optically transparent or translucent material, while in other aspects only the first substrate 70 is made of an optically transparent or translucent material. The first substrate 70 and the second substrate 86 may be made of the same or different materials and may have the same or different dimensions. According to some aspects, the second conductive layer 98 may include a metal reflector or one or more coatings configured as a partially reflective, partially transmissive ("transflective") coating. The inclusion of a metallic reflector or transflective coating may cause the electrochromic device 10 to be at least partially reflective.

First and second conductive layers 82, 98 may include one or more layers of conductive material disposed on first and second substrates 70, 86, respectively. These layers serve as the electrodes (i.e., cathode and anode) of the electrochromic device 10. First conductive layer 82 and/or second conductive layerThe conductive material of layer 98 may be any suitable material including one or more of the following characteristics: (a) substantially transparent to visible and/or IR light; (b) bonds reasonably well with first substrate 70 and second substrate 86; (c) maintain adhesion with the first and second substrates 70, 86 when associated with the sealing member 106; (d) generally resistant to corrosion from the electrochromic device 10 or materials contained within the atmosphere; and/or (e) exhibit minimal diffuse or specular reflection and sufficient electrical conductance. Depending on the application, it may be desirable that only one of the first and second conductive layers 82, 98 be transparent, while the other conductive layer 82, 98 may be opaque. In some applications, both first conductive layer 82 and second conductive layer 98 may be transparent. The conductive material forming first conductive layer 82 and second conductive layer 98 may be the same or different. Non-limiting examples of conductive materials that may be used to form first conductive layer 82 and/or second conductive layer 98 may include fluorine doped tin oxide (FTO), such as TEC^TMGlass, indium/tin oxide (ITO), doped zinc oxide, Indium Zinc Oxide (IZO), aluminum doped zinc oxide (AZO), and metal oxide/metal oxide (where the metal oxide may be replaced with a metal carbide, a metal nitride, a metal sulfide, etc.).

While aspects of the present disclosure are described in the context of electrochromic device 10, aspects of the present disclosure may also be used in the context of other electrochromic devices, non-limiting examples of which include those described in: U.S. Pat. No. 5,818,625 entitled "Electrochromic Rearview Mirror Incorporating a Third Surface Metal Reflector" granted on 6.10.1998; U.S. Pat. No. 6,597,489 entitled "Electrode Design for Electrical Devices" granted on day 22/7/2003; and U.S. patent No. 6,700,692 entitled "Electrochromic read Mirror Assembly incorporated a Display/Signal Light" entitled "on 3/2/2004, all of which are incorporated herein by reference in their entirety, including all references incorporated therein.

Still referring to fig. 1 and 2A-E, the electrochromic device 10 includes an electro-optic element 140 at least partially defined by the first and second substrates 70, 86, the chamber 110, and the electrochromic medium 124. The electro-optic element 140 allows the electrochromic device 10 to be operable between a transparent or clear state, in which it allows light having wavelengths within the predetermined wavelength range to pass therethrough, and a darkened state, in which some or no light having wavelengths within the predetermined wavelength range is transmitted through the electro-optic element 140 (i.e., the electro-optic element 140 is substantially opaque or partially opaque to light having wavelengths within the predetermined wavelength range). The electro-optic element 140 is operable between a substantially clear state and substantially dark or darkened states and intermediate states therein. The darkened state of the electro-optical element 140 may be defined relative to the transmittance of the substantially clear state. According to one aspect of the present disclosure, the electro-optic element 140 may have a transmittance of greater than about 15%, greater than about 25%, greater than about 50%, greater than about 55%, or greater than about 85% in the substantially transparent or clear state. The sum of the percentages of reflectivity, transmissivity and absorptivity of the electro-optical element 140 is 100%. In some aspects, the electro-optic element 140 may have a transmission of less than about 10%, less than about 1%, less than about 0.1%, less than about 0.01%, or less than about 0.001% in the substantially darkened state.

The seal 106 may traverse a substantial perimeter of the first and second substrates 70, 86 and be configured to cooperate with the first and second substrates to define the chamber 110 as substantially sealed. The seal 106 may be applied to the first substrate 70 or the second substrate 86 by methods commonly used in the Liquid Crystal Display (LCD) industry, such as by screen printing or dispensing. In one example, the seal 106 may include first and second seals as components of the seal 106. In one example, annular bands of first and second highly conductive materials are optionally deposited around the perimeter of first substrate 70 and second substrate 86, respectively, and conductive structures (e.g., clips or wires) are secured to the highly conductive materials and spatially separated from one another. The conductive structure may supply a voltage to the annular bands of first and second highly conductive materials to generate a voltage across the electro-optic element 140, thereby reversibly driving the electro-optic element 140 between the substantially dark and substantially clear states. The annular bands of first and second highly conductive materials may comprise silver, gold, copper or aluminum (e.g., in the form of metallic flakes or particles dispersed in a host material).

Referring to fig. 2A-E, the electro-optic element 140 includes an electrochromic medium, at least one cathode component, and at least one anode component. The anode and cathode components may alternatively be referred to as chromophores or electrochromic molecules. According to some aspects of the present disclosure, the anode and/or cathode components may be polymers and/or monomers. In some aspects, both the cathode and anode components are electroactive and at least one of them is electrochromic. It is to be understood that, regardless of its ordinary meaning, the term "electroactive" may refer to a material whose oxidation state changes upon exposure to a particular potential difference. Additionally, it is to be understood that, regardless of its ordinary meaning, the term "electrochromic" may refer to a material whose extinction coefficient changes at one or more wavelengths upon exposure to a particular potential difference. As described herein, an electrochromic component includes a material whose color or opacity can be affected by an electrical current such that when an electric field is applied to the material, the color or opacity changes from a first state to a second state.

According to one aspect of the disclosure, a cathode component comprises a viologen-based compound of formula (I):

wherein each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group; each R₂Is hydrogen; each R₃Independently hydrogen or alkyl; each R₄Independently hydrogen, alkyl or hydroxyalkyl; and X^-Is an anion. The compounds of formula (I) typically include a 3, 3' ethylene bridge wherein each R is₄May be hydrogen, alkyl or hydroxyalkyl. The viologen-based compounds of formula (I) may be characterized by a low rate of dimer formation or by the absence of dimer formation.

As used herein, "alkyl" groups include straight and branched alkyl groups having 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, 6 to 20 carbon atoms, 6 to 12 carbon atoms, 8 to 20 carbon atoms, or 12 to 20 carbon atoms. As used herein, "alkyl group" includes cycloalkyl groups as defined below. The alkyl group may be substituted or unsubstituted. Examples of straight chain alkyl groups include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl groups. Non-limiting examples of branched alkyl groups include isopropyl, sec-butyl, tert-butyl, neopentyl, and isopentyl groups. Representative substituted alkyl groups may be substituted one or more times with, for example, amino, thio, hydroxy, cyano, alkoxy, and/or halogen groups such as F, Cl, Br, and I groups. As used herein, the term haloalkyl is an alkyl group having one or more halo groups. In some aspects, haloalkyl refers to a perhaloalkyl group. As used herein, C when used in front of a group_m-C_nSuch as C₁-C₁₂、C₁-C₈Or C₁-C₆Refers to a group containing m to n carbon atoms.

As used herein, "substituted" refers to an alkyl group in which one or more of the bonds contained therein to a hydrogen atom is replaced with a bond to a non-hydrogen or non-carbon atom. Substituted groups also include groups in which one or more bonds to a carbon or hydrogen atom are replaced with one or more bonds to a heteroatom, including double or triple bonds. Thus, unless otherwise specified, a substituted group will be substituted with one or more substituents. In some aspects, a substituted group is substituted with 1, 2,3, 4, 5, or 6 substituents. Examples of substituent groups include: halogen (i.e., F, Cl, Br, and I); a hydroxyl group; alkoxy, alkenyloxy, alkynyloxy, aryloxy, aralkyloxy, heterocyclyloxy, and heterocyclyloxy groups; carbonyl (oxo); a carboxyl group; an ester; a carbamate; an oxime; a hydroxylamine; an alkoxyamine; an arylalkoxyamine; a thiol; a thioether; a sulfoxide; a sulfone; a sulfonyl group; a sulfonamide; an amine; an N-oxide; hydrazine; a hydrazide; hydrazone; an azide; an amide; urea; amidines; guanidine; an enamine; an imide; an isocyanate; an isothiocyanate; a cyanate ester; a thiocyanate; an imine; a nitro group; nitriles (i.e., CN); and the like. Such substitutions include solubility enhancing groups as described in U.S. patent No. 6,445,486 issued on 9/3 of 2002.

Cycloalkyl groups are cyclic alkyl groups such as, but not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Cycloalkyl groups may be substituted or unsubstituted. Cycloalkyl groups also include polycyclic cycloalkyl groups such as, but not limited to, norbornyl, adamantyl, bornyl, camphene, isobornene, and carenyl groups, and fused rings, non-limiting examples of which include naphthylalkyl. Cycloalkyl groups also include rings substituted with a straight or branched chain alkyl group as defined above. Representative substituted cycloalkyl groups may be mono-substituted or substituted more than once, non-limiting examples of which include: 2,2-, 2,3-, 2,4-, 2, 5-or 2, 6-disubstituted cyclohexyl radicals or mono-, di-or tri-substituted norbornyl or cycloheptyl radicals, which radicals may be substituted, for example, by alkyl, alkoxy, amino, thio, hydroxy, cyano and/or halogen radicals.

Non-limiting examples of suitable polymerizable functional groups include vinyl groups, acrylate groups, methacrylate groups, vinyl ether groups, hydroxyl groups, isocyanate groups, oxetane groups, and epoxy groups. According to one aspect, each R₁May be independently C comprising at least one substituted polymerizable functional group₁-C₂₀An alkyl group. In one aspect, a substituted alkyl group can comprise 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, 6 to 20 carbon atoms, 6 to 12 carbon atoms, 8 to 20 carbon atoms, or 12 to 20 carbon atoms.

Non-limiting examples of anions X include halide, borate, fluoroborate, tetraarylborate, hexafluorometal or metalloid, sulfate, sulfonate, sulfonamide, carboxylate, perchlorate, and tetrachloroferrocinate. Additional non-limiting examples of suitable anions X include: f^-、Cl^-、Br^-、I^-、BF₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、ClO₄ ^-、SO₃CF₃ ^-、N(CN)₂ ^-、N(CF₃SO₂)₂ ^-、C(CF₃SO₂)₃ ^-、N(SO₂C₂F₅)₂ ^-、Al(OC(CF₃)₃)₄ ^-Or BAR₄ ^-Wherein Ar is an aryl or fluoroaryl group. In one aspect, X^-Is BAr₄ ^-And Ar is a pentafluorophenyl group. In another aspect, X is tetrafluoroborate or a bis (trifluoromethanesulfonyl) imide anion. When shown in any of the compounds herein, multiple xs can be a single anion or a mixture of two or more such anions.

Fig. 3 illustrates an exemplary viologen-based compound according to formula (I) (example compound (I)) characterized by a low or absent rate of dimer formation according to one aspect of the present disclosure. In the example of instantiation of Compound (I), each R of formula (I)₁Is C containing a hydroxy substituent₆Alkyl radical, each R₂And R₃Is hydrogen, R₄Is hydrogen or an alkyl group, and each X^-Is an anion. According to one aspect, the length of the carbon chain of the alkyl group may be selected to be 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, 6 to 20 carbon atoms, 6 to 12 carbon atoms, 8 to 20 carbon atoms, or 12 to 20 carbon atoms.

According to another aspect of the present disclosure, electrochromic compounds include viologen-based compounds of formula (II):

wherein each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group; each R₂Is hydrogen; each R₄Independently hydrogen, alkyl or hydroxyalkyl; each R'₄Independently hydrogen, alkyl or hydroxyalkyl; and X is an anion. Compounds of formula (II) and formula (I)Analogously, with the difference that the compound of formula (II) also comprises a 5,5' ethylene bridge, in which R₄And R'₄May be hydrogen, alkyl or hydroxyalkyl. R₁R which may be selected from those described herein in relation to formula (I)₁Any of the materials described. R₄And R'₄R which may be selected from those described herein in relation to formula (I)₄Any of the materials described. The viologen-based compounds of formula (II) may be characterized by a low rate of dimer formation or by the absence thereof.

The viologen-based compounds of the formulae (I) and (II) according to the invention can be used in the form of a solution, a gel or a film as a cathode component in electrochromic media of electro-optical elements. The electrochromic medium may include a layer of material attached directly to or confined in close proximity to a conductive layer that remains attached or confined when its components are oxidized and/or reduced.

In one aspect, the viologen-based compounds of formulas (I) and (II) can be incorporated into a polymer film to form a cathode film. The viologen-based compounds of the present invention can be incorporated into the backbone of the polymeric chains forming the polymeric membrane and/or covalently bonded to the polymeric chains as pendant groups. For example, the cathode film may be a polymeric film comprising a plurality of polymeric chains consisting of a plurality of repeating monomeric units forming the backbone of the polymeric chains. In particular examples, the cathode film can comprise a copolymer of 4,4 'bipyridine and 1,4 dibromobutanetetrafluoroborate, a copolymer of 4, 4' -bipyridine and triethylene glycol tosylate, and/or a copolymer of 4,4 '-bipyridine and tetraethylene glycol tosylate, wherein at least a portion of the 4, 4' bipyridine can comprise a 3,3 '-ethylene and/or 5,5' -ethylene bridge according to formula (I) or (II). The cathode film may comprise a binder polymer (e.g., Polymethylmethacrylate (PMMA), polyvinyl formal, or polyethylene glycol), a plasticizer (e.g., propylene carbonate or γ -butyrolactone) that will help promote ionic conductivity, and a supporting electrolyte salt (e.g., tetraethylammonium tetrafluoroborate or lithium hexafluorophosphate). The viologen-based compounds of formulae (I) and (II) may form pendant groups attached to the polymer backbone or arranged between the monomer units of the backbone.

In another aspect, the cathode film can be a solid polymer or a gel polymer. For example, the polymer may be an acrylate-based polymer, which is dissolved in a solvent including the viologen-based compound of formula (I) or (II). This solution is then coated onto the conductive surface of the substrate, followed by removal of the solvent. The resulting film is an acrylate film, which may be hard or tacky to the touch. In another example, the polymer film can be a gel containing a solvent and the viologen-based compound of formula (I) or (II). Optionally, the polymer film may be subsequently crosslinked to improve mechanical stability. Other non-limiting examples of polymer matrix systems that may be used with the viologen-based compounds of formulas (I) and (II) include: polyacrylate, polymethacrylate, polyether, polyester, polycarbonate, polyurethane, polysiloxane, polysilane, polyacrylonitrile, polystyrene, polymethacrylonitrile, polyamide, polyimide, polyvinylidene halide, and copolymers or combinations of any two or more thereof. Other examples of polymeric matrix materials used in electrochromic devices can be found in U.S. patent nos. 6,635,194, 5,940,201, 5,928,572, and 9,964,828, which are incorporated herein by reference in their entirety.

According to one aspect, the viologen-based compounds of formulae (I) and (II) may comprise hydroxyl groups such that the compounds may be incorporated into the polymer matrix via a condensation reaction or may react with isocyanate functional groups to form a polyurethane-based polymer matrix. The amines may also be reacted with the isocyanate functional groups to form urea and biuret linkages. It is also within the scope of the present disclosure to employ other polymer matrix systems containing compounds of formula (I) and/or formula (II), which may be formed using a combination of a multifunctional epoxy resin and a curing agent such as an amine, alcohol, or anhydride, or by base or acid catalyzed homopolymerization. Non-limiting examples of materials that can be used as a polymer matrix to which the viologen-based compounds of formulas (I) and (II) are covalently bonded include: polymethylmethacrylate, polymethacrylate, polypropylene glycol methacrylate, polystyrene, polyurethane, polyether, polyester, polycarbonate, polysiloxane, polysilane, polyacrylonitrile, polymethacrylonitrile, polyamide, polyimide, polyvinylidene halide, and copolymers and combinations thereof. Other examples of polymeric matrix materials can be found in U.S. patent nos. 6,635,194, 5,940,201, 5,928,572, and 9,964,828, which are incorporated herein by reference in their entirety.

The anode component of the electrochromic medium may be any suitable solvent, film or gel-based material having incorporated therein an anode component capable of cooperating with the viologen-based compounds of formulae (I) and (II) to form an electro-optic element. The anode component may include an oxidizable compound, non-limiting examples of which include: metallocenes, 5, 10-dihydrophenazine, phenothiazine, phenoxazine, carbazole, triphenodithiazine, triphenodioxazine, ferrocene, substituted ferrocenium salts, phenazine, substituted phenazine, phenothiazine, substituted phenothiazines, including substituted dithiazines, thianes and substituted thianes, di-tert-butyldiethylferrocene, 5, 10-dimethyl-5, 10-Dihydrophenazine (DMP), 3,7, 10-trimethylphenothiazine, 2,3,7, 8-tetramethoxy-thianes, 10-methylphenothiazine, Tetramethylphenazine (TMP), bis (butyltriethylammonium) -p-methoxytriphenodithiazine (TPDT), 5, 10-bis (3-hydroxypropyldimethylammoniobutyl) -5, 10-dihydrophenazine bis (hexafluorophosphate), and 3, 10-dimethoxy-7, 14- (triethylammoniumbutyl) -triphenodithiazinebis (tetrafluoroborate).

In some aspects, the anode component may include a polymer film such as polyaniline, polythiophene, polymeric metallocene, or solid transition metal oxides including, but not limited to, oxides of vanadium, nickel, and iridium. In another aspect, the anode component includes a substituted or unsubstituted phenazine compound. For example, the anode component may include a substituted or unsubstituted 2, 7-dialkyl-5, 10-dihydrophenazine compound. In another example, at least one alkyl group attached to the 5, 10-dialkyl group of the phenazine compound contains at least 4 carbon atoms and does not contain any beta hydrogen atoms, and at least one alkyl group attached to the 2, 7-dialkyl group of the phenazine compound contains at least 4 carbons. In another example, at least one alkyl group attached to the 5, 10-dialkyl group of the phenazine compound comprises a substituted or unsubstituted neopentyl group, and at least one alkyl group attached to the 2, 7-dialkyl group of the phenazine compound comprises a substituted or unsubstituted isopropyl, isobutyl, (2-ethylbutyl), or (2-propylpentyl) group. In another example, at least one alkyl group attached to the 5, 10-dialkyl group of the phenazine compound comprises a neopentyl group and at least one alkyl group attached to the 2, 7-dialkyl group of the phenazine compound comprises a 2-ethyl-1-butanol group. In yet another example, at least one alkyl group attached to the 5, 10-dialkyl group of the phenazine compound comprises a neopentyl group and at least one alkyl group attached to the 2, 7-dialkyl group of the phenazine compound comprises an isobutyl group.

According to some aspects, the concentration of the viologen-based compound and/or the anode component of formulae (I) and (II) in the electrochromic medium is from about 1 millimolar (mM) to about 500mM, from about 2mM to about 100mM, from about 5mM to about 50mM, from about 40mM to about 50mM, from about 60mM to about 90mM, or from about 70mM to about 80 mM. In one aspect, the concentration of the viologen-based compounds of formulae (I) and (II) is about 50mM, about 50mM to about 100mM, about 60 to about 90mM, or about 70mM to about 80 mM. In one aspect, the concentration of the anode component is at least 5mM or about 2mM to about 100mM, about 5mM to about 50mM, or about 7mM to about 50 mM.

The electrochromic medium may also contain an electrolyte, which may be in the form of a solvent and a salt. The salt may be a metal salt or an ammonium salt. Non-limiting examples of suitable solvents for use in the electrolyte include: 3-methyl sulfolane, dimethyl sulfoxide, dimethylformamide, tetraglyme and other polyethers; alcohols, such as ethoxyethanol; nitriles such as acetonitrile, glutaronitrile, 3-hydroxypropionitrile and 2-methylglutaronitrile; ketones, including 2-acetylbutyrolactone and cyclopentanone; cyclic esters including beta-propiolactone, gamma-butyrolactone, and gamma-valerolactone; propylene Carbonate (PC), ethylene carbonate; and a homogeneous mixture thereof. Non-limiting examples of suitable salts include: a metal or ammonium salt of an anion having F^-、Cl^-、Br^-、I^-、BF₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、ClO₄ ^-、SO₃CF₃ ^-、N(CF₃SO₂)₂ ^-、C(CF₃SO₂)₃ ^-、N(SO₂C₂F₅)^-、Al(OC(CF₃)₃)₄ ^-Or BAR₄ ^-Wherein Ar is an aryl or fluoroaryl group such as, but not limited to, C₆H₅、3,5-(CF₃)₂C₆H₃]₄Or C₆F₅The metal or ammonium salt being, for example, Li⁺、Na⁺、K⁺、NR’₄ ⁺(wherein each R' is independently H, alkyl, or cycloalkyl).

The electrochromic medium may optionally include additional materials such as light absorbers, light stabilizers, heat stabilizers, antioxidants, oxygen scavengers, thickeners, viscosity modifiers, toners, redox buffers, and mixtures of any two or more of such materials. Non-limiting examples of UV stabilizers may include ethyl-2-cyano-3, 3-diphenyl acrylate; acrylic acid (2-ethylhexyl) -2-cyano-3, 3-diphenyl ester; 2- (2 '-hydroxy-4' -methylphenyl) benzotriazole, available under the trade name Ciba-Geigy CorpSelling P; 3- [3- (2H-benzotriazol-2-yl) -5- (1, 1-dimethylethyl) -4-hydroxyphenyl]Pentyl propionate sold by Ciba-Geigy Corp213 prepared via conventional hydrolysis followed by conventional esterification (hereinafter referred to as "PE "); 2, 4-dihydroxybenzophenone; 2-hydroxy-4-methoxybenzophenone; and 2-ethyl-2' -ethoxyalaninamide.

Fig. 2A, 2C, and 2D illustrate an exemplary configuration of an electro-optic element 140 that includes a cathode film 122 comprising a low-dimerization viologen-based compound of formula (I) or (II) according to one aspect of the disclosure, wherein at least a portion of the compound of formula (I) and/or (II) is covalently incorporated into the film. As illustrated in fig. 2A, the cathode film 122 may be used in the electro-optic element 140 in combination with an anode solution or gel 126. The cathode film 122 may be disposed on the first conductive layer 82 and the anode solution or gel 126 may be disposed on the second conductive layer 98. Optionally, the relative positions of the cathode film 122 and the anode solution or gel 126 may be reversed. The anode solution or gel 126 may be an electrochromic solution or gel including any suitable anode composition. Non-limiting examples of suitable Electrochromic gels can be found in U.S. patent No. 6,268,950 entitled "Electrochromic Gel with Two Thin Glass Elements and a geled Electrochromic Medium" and U.S. patent No. 7,001,540 entitled "Electrochromic Medium having a Self-sealing Cross-linked Polymer Gel and Associated Electrochromic Device," which are all incorporated herein by reference in their entirety.

Additionally, the anode solution or gel 126 may contain one or more electrolytes configured to facilitate electrical communication of the first and second electrically conductive layers 82, 98 across the anode solution or gel 126 and the cathode film 122. The anode solution or gel 126 may be in a semi-liquid state capable of transporting the anode components to the cathode components within the cathode membrane 122. For example, the anode solution or gel 126 may permeate the cathode membrane 122 along with one or more electrolyte salts and/or anode components. In the depicted example, either or both of the cathode and anode components of the cathode film 122 and anode solution or gel 126, respectively, can be electrochromic.

Fig. 2B illustrates one exemplary configuration of an electro-optic element 140 that includes a cathode solution or gel 138 that includes a low-dimerization viologen-based compound of formula (I) or (II) according to one aspect of the present disclosure. As illustrated in fig. 2B, a cathodic solution or gel 138 may be used in the electro-optic element 140 with the anodic film 134 of fig. 2B-D. The cathodic solution or gel 138 may be disposed on the first conductive layer 82 and the anodic film 134 may be disposed on the second conductive layer 98, or vice versa. The cathodic solution or gel 138 may be an electrochromic gel that may contain one or more electrolytes configured to facilitate electrical communication of the first and second electrically conductive layers 82, 98 across the cathodic solution or gel 138 and the anodic membrane 134. According to one aspect, the cathodic solution or gel 138 may be in a semi-liquid state capable of transporting the cathodic components to the anodic components within the anodic membrane 134. For example, the cathodic solution or gel 138 may permeate the anodic membrane 134 with one or more electrolyte salts and/or cathodic components. In the depicted example, either or both of the anode and cathode components of the anode membrane 134 and cathode solution or gel 138, respectively, may be electrochromic.

The anode membrane 134 can be any suitable membrane having an anode component incorporated therein. For example, the anodic film 134 can be a polymeric film comprising a plurality of polymeric chains composed of a plurality of repeating monomeric units forming the backbone of the polymeric chains. In some examples, the backbone of the polymer chain may have one or more pendant groups extending therefrom. In one example, the anodic film 134 can include a copolymer of 2, 7-bis (2-hydroxyethyl) -5,10 hydro-5, 10-bis (neopentyl) phenazine and toluylene-2, 4-diisocyanate. The anodic film 134 can include a binder polymer (e.g., polymethyl methacrylate (PMMA), polyvinyl formal, or polyethylene glycol), a plasticizer (e.g., propylene carbonate or γ -butyrolactone) that will help promote ionic conductivity, and a supporting electrolyte salt (e.g., tetraethylammonium tetrafluoroborate or lithium hexafluorophosphate). In examples where the electro-optic structure 114 includes an anodic film 134, the anodic component can be disposed between the monomeric units of the backbone. In other examples, the side groups may additionally or alternatively comprise an anode component.

Referring now to the example depicted in fig. 2C, the electro-optic element 140 includes both the cathode film 122 and the anode film 134. The cathode membrane 122 and the anode membrane 134 may be in direct contact with each other, or may be separate (e.g., separated by a membrane configured to facilitate electrical or ion exchange). As explained above, the cathode film 122 and the anode film 134 may be polymer films comprising cathode components and anode components disposed along the backbone of the polymeric chains of the cathode film 122 and the anode film 134, respectively, or disposed on the side groups of the polymeric chains, respectively.

Referring now to the example depicted in fig. 2D, the electro-optic element 140 includes both the cathode film 122 and the anode film 134 and additionally an electrolyte layer 146 separating the films 122, 134. Electrolyte layer 146 may be a gel (e.g., a semi-liquid configured to permeate cathode membrane 122 and anode membrane 134) or a polymer electrolyte. In examples where a polymer electrolyte is employed as the electrolyte layer 146, the polymer electrolyte may include styrene-ethylene random copolymer, polystyrene- (ethylene-butylene random copolymer) block copolymer, styrene-ethylene random copolymer, polystyrene-poly (ethylene/butylene) -polystyrene block copolymer, poly (ethylene glycol), poly (methyl methacrylate), other polymer electrolytes, and/or combinations thereof. Electrolyte layer 146 may partially permeate cathode film 122 and anode film 134.

Referring now to the example depicted in fig. 2E, the electro-optic element 140 can include an electro-optic film 154. Electro-optic film 154 can be a polymeric material composed of a plurality of polymeric chains, similar to cathode film 122 and anode film 134 (fig. 2C and 2D). In such an example, the electro-optic film 154 can contain both the anode component and the cathode component on the backbone of the polymer chain and/or as a pendant group. In some examples, both the anode component and the cathode component may be located on the same polymer chain, while in other examples, the anode component and the cathode component may be located on different polymer chains. Alternatively, the electro-optic film 154 can be a solution or gel containing both the anode and cathode materials that are not bonded to a polymer but are free to diffuse through the electro-optic film 154.

Conventional electro-optic elements employing viologens that exhibit dimerization behavior may undergo the observed change in color appearance based on the formation of viologen dimers. The color change observed due to viologen dimerization may be affected by a variety of factors, examples of which include temperature, concentration of viologen reducing free radicals, potential applied to the electrochromic device, choice of solvent, and/or choice of plasticizer. For example, temperature can affect the degree of dimerization, with lower temperatures often resulting in higher dimerization rates. Higher concentrations and potentials may also increase the rate of dimer formation. In addition, conditions that restrict viologen movement, such as incorporation into membranes or cross-linking, may increase dimerization.

The viologen-based compounds of formulae (I) and (II) of the present disclosure include features that can reduce the rate of dimer formation, in particular, can reduce the rate of dimer formation under conditions typically experienced by electrochromic devices such as mirrors and windows. The viologen-based compounds of formulae (I) and (II) of the present disclosure comprise structural components in the form of one or two ethylene bridges, respectively, which have been found to reduce the rate of dimer formation. The viologen-based compounds of formulae (I) and (II) of the present disclosure can be used to reduce the color change of an electrochromic device due to dimerization, and can also result in a faster clearance rate (clearing rate) of the electrochromic device compared to devices that exhibit higher dimer formation rates. In some cases, conventional viologen dimers can reduce the coloration and the clearance rate of electrochromic devices compared to the monocrypsin. The viologen-based compounds of formulae (I) and (II) of the present disclosure exhibit lower dimer formation rates and are therefore less likely to form dimers that would slow the rate of coloration and clearance in electrochromic devices.

The viologen-based compounds of formulae (I) and (II) of the present disclosure are useful in electrochromic media for electro-optic elements that can be used in a variety of different electrochromic devices, non-limiting examples of which include interior and exterior mirror assemblies, interior and exterior windows, skylights, heads-up displays, display screens, filter assemblies, eyewear, cameras, and display panels.

The following examples describe various features and advantages provided by the present disclosure and are in no way intended to limit the invention and the appended claims.

Examples

Example 1

Fig. 4 illustrates an exemplary synthesis scheme 200 for synthesizing a hypodimerized viologen-based compound of example compound (I). Although the synthesis is discussed in the context of the example compound (I), it is understood that the synthetic process is applicable to other hypodimerized viologen-based compounds of formulas (I) and (II). It is also understood that the compounds of example compound (I) may be synthesized according to other procedures. It is also understood that the synthetic scheme 200 may include additional or alternative steps without departing from the scope of the present disclosure.

Still referring to FIG. 4, step 202 is a reductive coupling step in which compound (A) is combined with titanium chloride (TiCl)₄) Zinc and Tetrahydrofuran (THF) in the "McMurry reactionAre combined to form an olefin compound (B). Then, at step 204, compound (B) undergoes a double bond reduction/hydrogenation process using a palladium on carbon catalyst and an ether solvent to form compound (C). Step 206 forms compound (D) in a pyridine coupling reaction that forms a biaryl bond and results in acylation of the amine. At 208, the diacylated dihydropyridine compound (D) is oxidized and the acyl group is removed in a hydrolysis reaction to yield compound (E). Amine alkylation to form at each R at step 210₁Example compounds (I) having hexanol functionality in place.

The viologen-based compounds of example compound (I) so formed are useful as cathode components in electrochromic media for use in electro-optic elements and electrochromic devices as described herein.

The present disclosure encompasses the following non-limiting aspects. To the extent not already described, any of the features of the following aspects may be combined, in part or in whole, with the features of any one or more of the other aspects of the disclosure to form further aspects, even if such combinations are not explicitly described.

According to a first aspect of the present disclosure, an electro-optical element comprises a low-dimerization electrochromic compound of formula (I):

wherein:

each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group;

each R₂Is hydrogen;

each R₃Independently hydrogen or alkyl;

each R₄Independently hydrogen, alkyl or hydroxyalkyl; and is

X^-Is an anion.

The electro-optical element according to the first aspect, wherein the polymerizable functional group is at least one selected from a vinyl group, an acrylate group, a methacrylate group, a vinyl ether group, a hydroxyl group, an isocyanate group, an oxetane group and an epoxy group.

The electro-optical element according to the first aspect or any intervening aspect, wherein each R₄Is a methyl group.

The electro-optic element according to the first aspect or any intervening aspect, wherein at least one R₄Including polymerizable functional groups.

The electro-optic element according to the first aspect or any intervening aspect, wherein at least one R₁Including polymerizable functional groups.

The electro-optic element according to the first aspect or any intervening aspect, wherein the electrochromic compound of formula (I) is one of dissolved in a solvent, incorporated into a gel, or incorporated into a polymer film.

The electro-optic element according to the first aspect or any intervening aspect, wherein the electrochromic compound of formula (I) is at least one of incorporated into a backbone of polymeric chains forming the polymeric film or covalently bonded as a pendent group to the polymeric chains of the polymeric film.

The electro-optical cell according to the first aspect or any intervening aspect, wherein X^-Is selected from F^-、Cl^-、Br^-、I^-、BF₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、ClO₄ ^-、SO₃CF₃ ^-、N(CN)₂ ^-、C(CF₃SO₂)₃ ^-、N(SO₂C₂F₅)₂ ^-、N(CF₃SO₂)₂ ^-And Al (OC (CF)₃)₃)₄ ^-At least one of (a).

The electro-optic element according to the first aspect or any intervening aspect, further comprising an electrochromic medium comprising an electrochromic compound of formula (I) and a chamber defined at least in part by the first electrically conductive layer of the first substrate, the second electrically conductive layer of the second substrate, and a sealing member joining the first substrate and the second substrate, wherein the electrochromic medium is disposed within the chamber.

According to a second aspect of the present disclosure, an electrochromic medium for use in an electro-optical element comprises a low-dimerization electrochromic compound of the formula (I):

wherein:

each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group;

each R₂Is hydrogen;

each R₃Independently hydrogen or alkyl;

each R₄Independently hydrogen, alkyl or hydroxyalkyl; and is

X^-Is an anion.

The electrochromic medium according to the second aspect, wherein the polymerizable functional group is selected from at least one of a vinyl group, an acrylate group, a methacrylate group, a vinyl ether group, a hydroxyl group, an isocyanate group, an oxetane group, and an epoxy group.

The electrochromic medium according to the second aspect or any intervening aspect, wherein each R₄Is a methyl group.

The electrochromic medium according to the second aspect or any intervening aspect, wherein at least one R₄Including polymerizable functional groups.

The electrochromic medium according to the second aspect or any intervening aspect, wherein at least one R₁Including polymerizable functional groups.

The electrochromic medium according to the second aspect or any intervening aspect, wherein the electrochromic compound of formula (I) is one of dissolved in a solvent, incorporated into a gel, or incorporated into a polymer film.

According to the second aspect or any interveningThe electrochromic medium of aspect, wherein X^-Is selected from F^-、Cl^-、Br^-、I^-、BF₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、ClO₄ ^-、SO₃CF₃ ^-、N(CN)₂ ^-、C(CF₃SO₂)₃ ^-、N(SO₂C₂F₅)₂ ^-、N(CF₃SO₂)₂ ^-And Al (OC (CF)₃)₃)₄ ^-At least one of (a).

According to a third aspect of the present disclosure, an electro-optical element comprises a low-dimerization electrochromic compound of formula (II):

wherein:

each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group;

each R₂Is hydrogen;

each R₄Independently hydrogen, alkyl or hydroxyalkyl;

each R'₄Independently hydrogen, alkyl or hydroxyalkyl; and is

X is an anion.

The electro-optical element according to the third aspect, wherein the polymerizable functional group is at least one selected from a vinyl group, an acrylate group, a methacrylate group, a vinyl ether group, a hydroxyl group, an isocyanate group, an oxetane group and an epoxy group.

The electro-optic element of the third aspect or any intervening aspect, wherein each R₄And each R'₄Is a methyl group.

The electro-optic element of the third or any intervening aspect, wherein at least one R₄And at least one R'₄Or at least one R₄And at least one R'₄Including polymerizable functional groups.

The electrochromic medium according to the second aspect or any intervening aspect, wherein at least one R₁Including polymerizable functional groups.

The electro-optic element according to the third aspect or any intervening aspect, wherein the electrochromic compound of formula (II) is one of dissolved in a solvent, incorporated into a gel, or incorporated into a polymer film.

The electro-optic element according to the third aspect or any intervening aspect, wherein the electrochromic compound of formula (II) is at least one of incorporated into a backbone of polymeric chains forming the polymeric film or covalently bonded as a pendent group to the polymeric chains of the polymeric film.

The electro-optical element according to the third aspect or any intervening aspect, wherein X^-Is selected from F^-、Cl^-、Br^-、I^-、BF₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、ClO₄ ^-、SO₃CF₃ ^-、N(CN)₂ ^-、C(CF₃SO₂)₃ ^-、N(SO₂C₂F₅)₂ ^-、N(CF₃SO₂)₂ ^-And Al (OC (CF)₃)₃)₄ ^-At least one of (a).

The electro-optic element according to the third aspect or any intervening aspect, further comprising an electrochromic medium comprising an electrochromic compound of formula (II) and a chamber defined at least in part by the first electrically conductive layer of the first substrate, the second electrically conductive layer of the second substrate, and a sealing member joining the first substrate and the second substrate, wherein the electrochromic medium is disposed within the chamber.

According to a fourth aspect of the present disclosure, an electrochromic medium for use in an electro-optical element comprises a low-dimerization electrochromic compound of the formula (II):

wherein:

each R₁Independently an alkyl group, a hydroxyalkyl group, or an alkyl group substituted with at least one polymerizable functional group;

each R₂Is hydrogen;

each R₃Independently hydrogen or alkyl;

each R₄Independently hydrogen, alkyl or hydroxyalkyl;

each R'₄Independently hydrogen, alkyl or hydroxyalkyl; and is

X^-Is an anion.

The electrochromic medium according to the fourth aspect, wherein the polymerizable functional group is selected from at least one of a vinyl group, an acrylate group, a vinyl ether group, a hydroxyl group, an oxetane group, and an epoxy group.

The electrochromic medium according to the fourth or any intervening aspect, wherein each R is₄And each R'₄Is a methyl group.

The electrochromic medium according to the fourth or any intervening aspect, wherein at least one R₄And at least one R'₄Or at least one R₄And at least one R'₄Including polymerizable functional groups.

The electrochromic medium according to the second aspect or any intervening aspect, wherein at least one R₁Including polymerizable functional groups.

The electrochromic medium according to the fourth aspect or any intervening aspect, wherein the electrochromic compound of formula (I) is one of dissolved in a solvent, incorporated into a gel, or incorporated into a polymer film.

The electrochromic medium according to the fourth or any intervening aspect, wherein X^-Is selected from F^-、Cl^-、Br^-、I^-、BF₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、ClO₄ ^-、SO₃CF₃ ^-、N(CN)₂ ^-、C(CF₃SO₂)₃ ^-、N(SO₂C₂F₅)₂ ^-、N(CF₃SO₂)₂ ^-And Al (OC (CF)₃)₃)₄ ^-At least one of (a).

It should be understood by those skilled in the art that the described disclosure and construction of other components is not limited to any particular materials. Other exemplary embodiments of the disclosure disclosed herein can be formed from a wide variety of materials, unless otherwise described herein.

For the purposes of this disclosure, the term "coupled" (in all its forms: coupled, coupling, coupled, etc.) generally means the joining of two (electrical or mechanical) components to each other, directly or indirectly. Such engagement may be stationary in nature or movable in nature. Such joining may be accomplished using two (electrical or mechanical) components and any additional intermediate members that are integrally formed as a single unitary body with each other or with both components. Unless otherwise specified, such engagement may be permanent in nature, or removable or releasable in nature.

It is also noted that the construction and arrangement of the elements of the disclosure as shown in the exemplary embodiments is illustrative only. Although only a few embodiments of the present innovations have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, integrally formed elements may be constructed of multiple parts or elements shown as multiple parts may be integrally formed, the operation of the interface may be reversed or otherwise varied, the length or width of the structure and/or members or connectors or other elements of the system may be varied, the nature or number of adjustment positions between the elements may be varied. It should be noted that the elements and/or components of the system may be constructed of any of a wide variety of materials that provide sufficient strength or durability, and may take any of a wide variety of colors, textures, and combinations. Accordingly, all such modifications are intended to be included within the scope of this innovation. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the desired and other exemplary embodiments without departing from the spirit of the present innovations.

It is understood that any described process or step within a described process may be combined with other disclosed processes or steps to form structures within the scope of the present disclosure. The exemplary structures and processes disclosed herein are for illustrative purposes and are not to be construed as limiting.

It is also to be understood that variations and modifications can be made on the above-described structures and methods without departing from the concepts of the present disclosure, and further it is to be understood that such concepts are intended to be covered by the appended claims unless these claims by their language expressly state otherwise.