Dendrimers for modulating magnetic properties of nanoparticles and hybrid nanoparticles formed therefrom
阅读说明：本技术 调整纳米颗粒磁特性的枝状体和由其形成的混合纳米颗粒 (Dendrimers for modulating magnetic properties of nanoparticles and hybrid nanoparticles formed therefrom ) 是由 D.吉斯卡瑞安尼 H.云 J.D.李 B.唐尼奥 C.B.默里 L.马拉西 于 2017-12-05 设计创作，主要内容包括：本披露涉及一种混合纳米颗粒,该混合纳米颗粒包含：(a)金属核心或金属氧化物核心,以及(b)至少一个附接至该金属核心或金属氧化物核心的表面的枝状体,其中该至少一个枝状体衍生自本文描述的符合式(I)或(II)的化合物；以及含有此类混合纳米颗粒的膜。还描述了符合式(I)或(II)的化合物以及其在形成本披露的混合纳米颗粒中的用途。(The present disclosure relates to hybrid nanoparticles comprising (a) a metal core or metal oxide core, and (b) at least dendrimers attached to the surface of the metal core or metal oxide core, wherein the at least dendrimers are derived from a compound conforming to formula (I) or (II) described herein, and films containing such hybrid nanoparticles.)
1, hybrid nanoparticles, the hybrid nanoparticles comprising:
(a) a metal core or a metal oxide core, and
(b) at least dendrites attached to the surface of the metal core or metal oxide core,
wherein the at least dendrimers are derived from compounds conforming to formula (I) or (II):
X1-L1-R2(II)
wherein
Each occurrence of R1Is H or C1-C20An alkyl group, a carboxyl group,
each occurrence of D1And D2Each independently is C1-C20An alkylene group or a substituted alkylene group,
l at each occurrence1Is C1-C20An alkylene group or a substituted alkylene group,
each occurrence of R2And R3Each independently is H, C1-C38Alkyl radical, C2-C38Alkenyl or C2-C38An alkynyl group,
n is from 1 to 6;
X1is-COOR5、-PO3R6R7、-CN、
Wherein
R5、R6And R7Each independently is H or a hydrocarbyl group;
R8、R9、R10、R11、R12、R13、R14、R15、R16、R17and R18Each independently is H, OH, CN, halogen, COOH or a hydrocarbyl group; and is
Wherein R is1、D1And D2、L1、R2And R3Each optionally interrupted by or more divalent moieties.
2. The mixed nanoparticle according to claim 1, wherein the metal core comprises a transition metal, typically at least two different transition metals, more typically selected from the group consisting of Mn, Fe, Co, Ni, Cu and Zn.
3. The hybrid nanoparticle according to claim 1 or 2, wherein the metal core comprises nickel.
4. The mixed nanoparticle according to claim 1 or 2, wherein the metal oxide core comprises at least 3 different transition metals, typically of formula M1 xM2 yM3 zO4Wherein M is1、M2And M3Each independently selected from the group consisting of Mn, Fe, Co, Ni, Cu, and Zn; and the sum of x, y and z is 3.
5. The mixed nanoparticle of claim 4, wherein the metal oxide core comprises manganese, zinc, and iron.
6. The mixed nanoparticle of any of claims 1-5, wherein n is from 1 to 3.
7. The mixed nanoparticle of claim 6, wherein n is 2.
8. The mixed nanoparticle of any of claims 1-7, wherein X1is-COOR5or-PO3R6R7。
9. The mixed nanoparticle of any of claims 1-8, wherein R1Is methyl.
10. The hybrid nanoparticle of any of claims 1-9, wherein D1And D2Each is methylene.
11. The mixed nanoparticle of any of claims 1-10, wherein R2And R3Are each a quilt
12. The mixed nanoparticle of any of claims 1-11, wherein L1is-O-andinterrupted C12-an alkylene group.
13, a film comprising a plurality of the mixed nanoparticles of any one of claims 1-12 from .
14, A compound conforming to formula (I) or (II):
X1-L1-R2(II)
wherein
Each occurrence of R1Is H or C1-C20An alkyl group, a carboxyl group,
each occurrence of D1And D2Each independently is C1-C20An alkylene group or a substituted alkylene group,
l at each occurrence1Is C1-C20An alkylene group or a substituted alkylene group,
each occurrence of R2And R3Each independently is H, C1-C38Alkyl radical, C2-C38Alkenyl or C2-C38An alkynyl group,
n is from 1 to 6;
X1is-COOR5、-PO3R6R7、-CN、
Wherein
R5、R6And R7Each independently is H or a hydrocarbyl group;
R8、R9、R10、R11、R12、R13、R14、R15、R16、R17and R18Each independently is H, OH, CN, halogen, COOH or a hydrocarbyl group; and is
Wherein R is1、D1And D2、L1、R2And R3Each optionally interrupted by or more divalent moieties.
15. The compound of claim 14, wherein n is from 1 to 3.
16. The compound of claim 15, wherein n is 2.
17. The compound of any of claims , wherein X1is-COOR5or-PO3R6R7。
18. The compound of any of claims 14-17, wherein R is 1Is methyl.
19. The compound of any of claims , wherein D is1And D2Each is methylene.
20. The compound of any of claims 14-19, wherein R is 2And R3Are each a quiltInterrupted C17-an alkyl group.
21. The compound of any of claims , wherein L1is-O-and
22, a method for adjusting the permeability of a nanoparticle, the method comprising:
contacting the nanoparticle with a compound according to any of claims 14-21.
23. The method of claim 22, wherein the contacting step is ligand exchange.
Technical Field
The present disclosure relates to hybrid nanoparticles comprising a metal core or metal oxide core, and at least dendrimers attached to the surface of the metal core or metal oxide core, wherein the at least dendrimers are derived from a compound conforming to formula (I) or (II) as described herein.
Background
Magnetic nanoparticles such as Nanocrystals (NCs) have recently attracted a great deal of attention due to their potential application in data storage, AC electromagnetic devices, bioimaging, and targeted drug delivery, the collective magnetic properties of NCs depend on the size, shape, chemical composition, and assembled structure of the NCs and their interparticle distances (dipole-dipole interactions), which have been studied in terms of DC and AC magnetic properties.
Accordingly, there is an unresolved need to develop magnetic materials with increased FMR frequencies for use in miniaturized AC magnetic devices operating at radio frequencies, and methods for adjusting the magnetic properties of such materials. Herein, it is described to adjust the magnetic properties, such as permeability, of mixed nanoparticles by using surface-bound dendritic ligands.
Disclosure of Invention
In an th aspect, the disclosure relates to hybrid nanoparticles comprising:
(a) a metal core or a metal oxide core, and
(b) at least dendrites attached to the surface of the metal core or metal oxide core,
wherein the at least dendrimers are derived from compounds conforming to formula (I) or (II):
X1-L1-R2(II)
wherein
Each occurrence of R1Is H or C1-C20An alkyl group, a carboxyl group,
each occurrence of D1And D2Each independently is C1-C20An alkylene group or a substituted alkylene group,
l at each occurrence1Is C1-C20An alkylene group or a substituted alkylene group,
each occurrence of R2And R3Each independently is H, C1-C38Alkyl radical, C2-C38Alkenyl or C2-C38An alkynyl group,
n is from 1 to 6;
X1is-COOR5、-PO3R6R7、-CN、
Wherein
R5、R6And R7Each independently is H or a hydrocarbyl group;
R8、R9、R10、R11、R12、R13、R14、R15、R16、R17and R18Each independently is H, OH, CN, halogen, COOH or a hydrocarbyl group; and is
Wherein R is1、D1And D2、L1、R2And R3Each optionally interrupted by or more divalent moieties.
In a second aspect, the present disclosure relates to films comprising a plurality of the mixed nanoparticles described herein.
In a third aspect, the disclosure relates to compounds conforming to formula (I) or (II):
X1-L1-R2(II)
wherein
Each occurrence of R1Is H or C1-C20An alkyl group, a carboxyl group,
each occurrence of D1And D2Each independently is C1-C20An alkylene group or a substituted alkylene group,
l at each occurrence1Is C1-C20An alkylene group or a substituted alkylene group,
each occurrence of R2And R3Each independently is H, C1-C38Alkyl radical, C2-C38Alkenyl or C2-C38An alkynyl group,
n is from 1 to 6;
X1is-COOR5、-PO3R6R7、-CN、
Wherein
R5、R6And R7Each independently is H or a hydrocarbyl group;
R8、R9、R10、R11、R12、R13、R14、R15、R16、R17and R18Each independently is H, OH, CN, halogen, COOH or a hydrocarbyl group; and is
Wherein R is1、D1And D2、L1、R2And R3Each optionally interrupted by or more divalent moieties.
In a fourth aspect, the present disclosure relates to a method for adjusting the permeability of a nanoparticle, the method comprising contacting the nanoparticle with a compound conforming to formula (I) or (II) as described herein.
Drawings
FIG. 1 schematically shows (a) the -like structure of a dendrimer, (b) the spatial arrangement of the four different units that make up a typical dendrimer, and (c) the dendrimer fragments in a typical dendrimer.
Fig. 2 shows a TEM image of a single layer of: (a) synthesis of as received Ni NC, (b) Ni @ G0, (c) Ni @ G1, (d) Ni @ G2, (e) Ni @ G3; and (f) Mw/interparticle distance (Mw ═ molecular weight). The dashed line serves only as a guide for the eye.
FIG. 3 shows the preparation of compounds 13 to 16 (also referred to as G0 to G3, respectively)1Coverage of H spectra, and a fragment of 16(G3) with full signal attribution。
Fig. 4 shows (a) a low magnification TEM image and (b) a high magnification TEM image of MZF NC as synthesized and (c) a low magnification image and (d) a high magnification image of the same NC after ligand exchange with compound 17. The inset of fig. 4a is the selected area electron diffraction pattern of NC.
Figure 5 shows the distribution of interparticle distances before and after ligand exchange.
Fig. 6 shows ZFC curves for MZF NC before (squares) and after (circles) ligand exchange with compound 17.
Figure 7 shows (a) the real part of the relative permeability and b) the imaginary part of the relative permeability, and c) the loss tangent, before (squares) and after (circles) ligand exchange with compound 17 for MZF NCs from 10MHz to 500 MHz.
FIG. 8 shows μ 'normalized to 'r(μ′r/μ′r initial) Graph is shown.
Figure 9 shows DSC traces of compounds 13-17 of the present invention described herein.
Detailed Description
As used herein, the term "/ (a/an)", or "the" means " or more" or "at least (s)", unless otherwise specified.
As used herein, the term "comprising" includes "consisting essentially of … … and" consisting of … …. The term "comprising" includes "consisting essentially of and" consisting of.
Throughout this disclosure, different publications may be referenced and/or incorporated by reference. To the extent that the meaning of any language in such publications incorporated by reference herein conflicts with the meaning of the language of the present disclosure, the meaning of the language of the present disclosure shall prevail unless otherwise indicated.
As used herein, the term "(Cx-Cy)" with respect to an organic group, wherein x and y are each an integer, means that the group may contain from x carbon atoms to y carbon atoms per group.
As used hereinAs used herein, the term "alkyl" means a monovalent linear or branched saturated hydrocarbon radical, more typically a monovalent linear or branched saturated (C)1-C40) Hydrocarbyl groups such as, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, hexyl, 2-ethylhexyl, octyl, hexadecyl, octadecyl, eicosyl, docosyl, triacontyl (tricontyl), and forty-alkyl groups.
As used herein, the term "alkenyl" means a monovalent linear or branched unsaturated hydrocarbon group having or more double bonds, more typically a monovalent linear or branched unsaturated (C)2-C40) A hydrocarbyl group. According to the IUPAC nomenclature, a double bond may have either the E or Z configuration, and may be isolated or conjugated. Examples of alkenyl groups include, but are not limited to, vinyl, n-butenyl, oleyl, and oleyl.
As used herein, the term "alkynyl" means a monovalent linear or branched unsaturated hydrocarbon group having or more triple bonds, more typically a monovalent linear or branched unsaturated (C)2-C40) A hydrocarbyl group. Triple bonds may be isolated or conjugated. Examples of alkynyl groups include, but are not limited to, ethynyl, n-propynyl, and n-butynyl.
As used herein, the term "alkylene" means a divalent straight or branched chain saturated hydrocarbon group, more typically a divalent straight or branched chain saturated (C)1-C40) Hydrocarbyl radicals, such as, for example, methylene, ethylene, n-propylene, n-butylene, hexylene, 2-ethylhexylene, octylene, hexadecylene and octadecylene.
Any of the substituents described herein may be optionally substituted at or more carbon atoms with or more of the same or different substituents described herein.e., alkylene may be substituted at steps with alkyl any of the substituents described herein may be optionally substituted at or more carbon atoms with or more substituents selected from the group consisting of halogen, such as, for example, F, Cl, Br, and I, Nitro (NO)2) Cyano (CN), amino (NH)2) Carboxylate and benzoate (CO)2H、PhCO2H) And a hydroxyl group (OH).
The present disclosure relates to hybrid nanoparticles comprising:
(a) a metal core or a metal oxide core, and
(b) at least dendrites attached to the surface of the metal core or metal oxide core,
wherein the at least dendrimers are derived from compounds conforming to formula (I) or (II):
X1-L1-R2(II)
wherein
Each occurrence of R1Is H or C1-C20An alkyl group, a carboxyl group,
each occurrence of D1And D2Each independently is C1-C20An alkylene group or a substituted alkylene group,
l at each occurrence1Is C1-C20An alkylene group or a substituted alkylene group,
each occurrence of R2And R3Each independently is H, C1-C38Alkyl radical, C2-C38Alkenyl or C2-C38An alkynyl group,
n is from 1 to 6;
X1is-COOR5、-PO3R6R7、-CN、
Wherein
R5、R6And R7Each independently is H or a hydrocarbyl group;
R8、R9、R10、R11、R12、R13、R14、R15、R16、R17and R18Each independently is H, OH, CN, halogen, COOH or a hydrocarbyl group; and is
Wherein R is1、D1And D2、L1、R2And R3Each optionally interrupted by or more divalent moieties.
The metal core or metal oxide core comprises a metal, or a metal-containing alloy or intermetallic compound. Metals include, for example, main group metals, such as, for example, lead, tin, bismuth, antimony, and indium, and transition metals, for example, transition metals selected from the group consisting of: gold, silver, copper, nickel, cobalt, palladium, platinum, iridium, osmium, rhodium, ruthenium, rhenium, vanadium, chromium, manganese, niobium, molybdenum, tungsten, tantalum, titanium, zirconium, zinc, mercury, yttrium, iron, and cadmium. The metal core may comprise or consist of a metal or a metal-containing alloy or intermetallic compound.
In embodiments, the metal core or metal oxide core comprises a transition metal, typically at least two different transition metals.
In an embodiment, the metal core or metal oxide core comprises a transition metal, typically at least two different transition metals, more typically selected from the group consisting of Mn, Fe, Co, Ni, Cu and Zn.
In an embodiment, the hybrid nanoparticle comprises a metal core comprising nickel.
In an embodiment, the mixed nanoparticles comprise a metal oxide core.
In another embodiments, the metal oxide core includes at least 3 different transition metals1 xM2 yM3 zO4Wherein M is1、M2And M3Each independently selected from the group consisting of Mn, Fe, Co, Ni, Cu, and Zn; and the sum of x, y and z is 3.
In another embodiments, the metal oxide core includes manganese, zinc, and iron.
The hybrid nanoparticles of the present disclosure comprise at least dendrimers derived from a compound conforming to formula (I) or (II) attached to the surface of a metal or metal oxide core.
Dendritic polymers (dendrimers) generally include any known dendritic architecture, including dendrimers, dendrimers (dendrons), controlled hyperbranched polymers, dendrigraft molecules (dendrograms), and random hyperbranched polymers.
Dendrimers and dendrimers can be prepared by convergent or divergent synthesis. Divergent synthesis of dendrimers and dendrimers involves a molecular growth process that proceeds by successive, geometrically progressive addition of branches in a molecular direction radially outward, resulting in an ordered arrangement of layered branch shells. Convergent synthesis of dendrimers and dendrimers involves a growth process that begins where it will become a dendrimer or dendrimer surface and proceeds radially in the molecular direction towards a focus or core. Dendrimers may be ideal or undesirable, i.e. imperfect or defective. Imperfections are often the result of incomplete or unavoidable competing side reactions of the chemical reaction.
The -like structure of a dendrimer is schematically shown in FIG. 1a the center of the structure is a core 1, which is typically non-metallic in the example of FIG. 1a, the core has three arms or dendrimers however, -like the core can have any number of dendrimers.
Each dendrimer of the core begins at the th "shell" (shell) of the linked
FIG. 1b schematically shows a spatial arrangement of four different units forming a typical dendrimer structure, the center being a core 1, surrounded by at least shells of repeating
Depending on the number of dendrites of the core 1, the dendritic polymer structure can be divided into
Chemically reactive end-capping groups may be used to further steps to extend the dendritic growth or modify the surface of the dendritic molecule.
As used herein, the phrase "interrupted by or more divalent moieties" when used in conjunction with a substituent means that the substituent is modified, wherein or more divalent moieties are inserted into or more covalent bonds between atoms.
The or more divalent moieties may be selected from the group consisting of:
as used herein, an asterisk refers to a point of attachment.
Each occurrence of Ra-RkEach independently H, halogen (typically F) or alkyl. When R isa-RkWhen any of (a) are alkyl groups, the alkyl group may optionally be interrupted by or more divalent moieties as defined herein.
The algebra n is typically 1 to 6, more typically 1 to 4, still more typically 1-3. In an embodiment, n is 2.
In factIn the examples, X1is-COOR5or-PO3R6R7。
In the examples, R1Is methyl.
In the examples, D1And D2Each is methylene.
In the examples, R2And R3Each is C17In another examples, R2And R3Are each a quilt
In the examples, L1Is C12In another examples, L1is-O-and
The present disclosure relates to films comprising a plurality of mixed nanoparticles described herein the plurality of mixed nanoparticles can include mixed nanoparticles having the same or different effective diameters.
In an embodiment, the plurality of mixed nanoparticles includes mixed nanoparticles having the same effective diameter.
In another embodiments, the plurality of mixed nanoparticles includes mixed nanoparticles having different effective diameters.
The various properties of the mixed nanoparticles of the present disclosure and films containing these mixed nanoparticles can be determined using methods and instruments known to those of ordinary skill in the art.
For example, a combination of techniques including NMR and UV-Vis spectroscopy, thermogravimetric analysis (TGA), Transmission Electron Microscopy (TEM), and small angle x-ray scattering (SAXS) may be used, a TGA Q600 apparatus from thermal Analyzer, USA (TAInstructions) may be used, at a temperature range of 25 ℃ to 500 ℃N2TGA was performed at a heating rate of 30 ℃/min, while thermal transitions were determined at heating and cooling rates of 10 ℃/min on a Q2000 Differential Scanning Calorimeter (DSC) from thermal Analyzer, USA, equipped with a liquid nitrogen cooling system. SAXS can be performed in a vacuum beam path using a multi-angle X-ray scattering instrument equipped with a bruker nonius FR 59140 kV rotary anode generator operating at 85mA, Osmic Max-Flux optics, a 2D Hi-Star Wire detector, and pinhole collimation.
The disclosure also relates to compounds conforming to formula (I) or (II):
X1-L1-R2(II)
wherein
Each occurrence of R1Is H or C1-C20An alkyl group, a carboxyl group,
each occurrence of D1And D2Each independently is C1-C20An alkylene group or a substituted alkylene group,
l at each occurrence1Is C1-C20An alkylene group or a substituted alkylene group,
each occurrence of R2And R3Each independently is H, C1-C38Alkyl radical, C2-C38Alkenyl or C2-C38An alkynyl group,
n is from 1 to 6;
X1is-COOR5、-PO3R6R7、-CN、
Wherein
R5、R6And R7Each independently is H or a hydrocarbyl group;
R8、R9、R10、R11、R12、R13、R14、R15、R16、R17and R18Each independently is H, OH, CN, halogen, COOH or a hydrocarbyl group; and is
Wherein R is1、D1And D2、L1、R2And R3Each optionally interrupted by or more divalent moieties.
In embodiments, n is from 1 to 3.
In an embodiment, n is 2.
In the examples, X1is-COOR5or-PO3R6R7。
In the examples, R1Is methyl.
In the examples, D1And D2Each is methylene.
In the examples, R2And R3Are each a quilt
In the examples, L1is-O-and
The compounds according to formula (I) or (II) may be manufactured according to methods known to a person skilled in the art.
For example, suitable methods include:
reacting a compound represented by the structure of formula (III):
X1-G1(III)
wherein X1is-COOR5、-PO3R6R7、-CN、
Wherein
R5、R6And R7Each independently is H or a hydrocarbyl group; and is
R8、R9、R10、R11、R12、R13、R14、R15、R16、R17And R18Each independently is H, OH, CN, halogen, COOH or a hydrocarbyl group;
with a compound represented by the structure of formula (IV) or (V):
G2-R2(V)
wherein
Each occurrence of R1Is H or C1-C20An alkyl group, a carboxyl group,
each occurrence of D1And D2Each independently is C1-C20An alkylene group or a substituted alkylene group,
each occurrence of R2And R3Each independently is H, C1-C38Alkyl radical, C2-C38Alkenyl or C2-C38An alkynyl group,
n is from 1 to 6;
wherein R is1、D1And D2、R2And R3Each optionally interrupted by or more divalent moieties as defined herein;
each occurrence of G1Is capable of reacting with G2A substituent of the reactive group of (1) and
G2is capable of reacting with G1A substituent of the reactive group in (1) is a reactive group.
Algebraic n is typically 1 to 6, more typically 1 to 4, still more typically 1 to 3. In an embodiment, n is 2.
In the examples, X1is-COOR5or-PO3R6R7。
In the examples, R1Is methyl.
In the examples, D1And D2Each is methylene.
In the examples, R2And R3Each is C17In another examples, R2And R3Are each a quilt
G1Is capable of reacting with G2A substituent of the reactive group of (1) and G2Is capable of reacting with G1A substituent of the reactive group in (1) is a reactive group.
Typically, G1Is C1-C15-an alkyl group optionally interrupted by or more divalent moieties as defined herein, comprising the ability to react with G2The reactive group in (1) is a reactive group.
In embodiments, G1 comprises a reactive group selected from the group consisting of: -X, -NH2、-N3、-(C＝O)X、-Ph(C＝O)X、-SH、-CH＝CH2-C ≡ CH; wherein X is a leaving group.
In the examples, G1Is composed of-N3C of a radical1-C15-an alkyl group.
Typically, G2Is C1-C15-an alkyl group optionally interrupted by or more divalent moieties as defined herein, comprising the ability to react with G1The reactive group in (1) is a reactive group.
In the examples, G2Comprising a reactive group selected from the group consisting of: - (C ═ O) X, -CH ═ CH2、-C≡CH、-NH2、-N3-Ph (C ═ O) X, -SH, -X, -NCO, -NCS; wherein X is a leaving group.
Leaving groups are known to those of ordinary skill in the art. Suitable leaving groups include, but are not limited to, halide ions such as fluoride, chloride, bromide, and iodide; alkyl and aryl sulfonates such as methanesulfonate (mesylate) and p-toluenesulfonate (tosylate); and hydroxyl.
In the examples, G2Is a C comprising a-C.ident.CH group1-C15-alkyl, interrupted by-O-group.
In light of this disclosure, it will be understood that G1And G2The reactive groups above may be reversed.
The compounds represented by the structures of formulae (III), (IV) and (V) may be obtained from commercial sources or synthesized according to synthetic methods well known to those of ordinary skill in the art. Suitable synthetic methods known to those of ordinary skill in the art are described in well known articles including, but not limited to, M.B. Smith "March's Advanced Organic Chemistry: Reactions, Mechanisms, and structures", 7thedition (Wiley) [ "higher organic chemistry of Marxi: reactions, mechanisms and structures, 7 th edition (Willi Press) "](ii) a And Carey and Sunberg "Advanced organic chemistry, Part A: Structure and mechanics", 5thedition (springer) [ "advanced organic chemistry, part a: structure and mechanism ", 5 th edition (Schpringer Press)]And "Advanced Organic Chemistry: PartB: Reaction and Synthesis", 5thedition (springer) [ "advanced organic chemistry, part B: reaction and Synthesis ", 5 th edition (Schpringer Press)]。
The skilled artisan can select any reaction conditions suitable for the reaction step, including reaction vessels and equipment, according to concepts known in chemical processes.
Hybrid nanoparticles according to the present disclosure may be manufactured by a method comprising:
(i) producing a compound having formula (I) or (II) as described herein, and
(ii) (II) contacting the compound produced in step (I) having formula (I) or (II) with metal or metal oxide nanoparticles: thereby producing the mixed nanoparticles.
The production of the compound corresponding to formula (I) or (II) may be carried out using any method known to the skilled person. Typically, compounds conforming to formula (I) or (II) are produced as described herein.
After producing a compound according to formula (I) or (II), the compound is contacted with metal or metal oxide nanoparticles. The metal or metal oxide nanoparticles become the metal core or metal oxide core of the mixed nanoparticles.
The metal nanoparticles or metal oxide nanoparticles may be obtained from commercial sources or manufactured according to methods known in the art. The metal nanoparticles comprise a metal or a metal-containing alloy or intermetallic compound. Metals include, for example, main group metals, such as, for example, lead, tin, bismuth, antimony, and indium, and transition metals, for example, transition metals selected from the group consisting of: gold, silver, copper, nickel, cobalt, palladium, platinum, iridium, osmium, rhodium, ruthenium, rhenium, vanadium, chromium, manganese, niobium, molybdenum, tungsten, tantalum, titanium, zirconium, zinc, mercury, yttrium, iron, and cadmium. The metal nanoparticles may comprise or consist of a metal or a metal-containing alloy or intermetallic compound.
In embodiments, the metal nanoparticles or metal oxide nanoparticles comprise a transition metal, typically at least two different transition metals.
In an embodiment, the metal nanoparticles or metal oxide nanoparticles comprise a transition metal, typically at least two different transition metals, more typically selected from the group consisting of Mn, Fe, Co, Ni, Cu and Zn.
In an embodiment, the metal nanoparticles comprise nickel.
In an embodiment, the metal oxide nanoparticles comprise at least 3 different transition metals. Typically, the metal oxide nanoparticles have the formula M1 xM2 yM3 zO4Wherein M is1、M2And M3Each independently selected from the group consisting of Mn, Fe, Co, Ni, Cu, and Zn; and the sum of x, y and z is 3.
In another embodiments, the metal oxide nanoparticles comprise manganese, zinc, and iron.
The metal or metal oxide nanoparticles may optionally comprise an organic capping group, such as, for example, oleylamine or CTAB, prior to contacting with the compound conforming to formula (I) or (II).
For example, metal or metal oxide nanoparticles can be suspended in or more of the solvents described herein to form a th mixture, a compound conforming to formula (I) or (II) can be dissolved in or more of the solvents described herein to form a second mixture, then the th mixture and the second mixture can be combined and stirred to produce mixed nanoparticles.
The present disclosure relates to compositions comprising at least of the mixed nanoparticles described herein and a liquid carrier.
The composition of the present disclosure may be a dispersion in which the at least mixed nanoparticles are undissolved, but suspended in a liquid carrier.
The liquid carrier used in the compositions according to the present disclosure includes an organic solvent or a blend of organic solvents. In embodiments, the composition consists essentially of or consists of an organic solvent or blend of organic solvents. The blend of organic solvents comprises two or more organic solvents.
Organic solvents suitable for use in the liquid carrier may be polar or non-polar, protic or aprotic solvents. Examples of suitable organic solvents include, but are not limited to, chlorinated solvents, such as, for example, chloroform and dichloromethane; alkane solvents such as, for example, pentane, hexane, heptane, and isomers thereof; and alcohols such as, for example, n-propanol, isopropanol, ethanol and methanol, and alkylene glycol monoethers.
In an embodiment, the liquid carrier comprises hexane or an isomer thereof.
The liquid carrier of the compositions according to the present disclosure may also contain residual amounts of water as a result of, for example, the hygroscopic effect of the solvent of the liquid carrier or the reaction medium used to make the metal nanoparticles remaining. The amount of water in the composition is from 0 to 2% wt. relative to the total amount of the composition. Typically, the total amount of water in the composition is from 0 to 1% wt, more typically from 0 to 0.5% wt, still more typically from 0 to 0.1% wt, relative to the total amount of the composition. In embodiments, the compositions of the present disclosure are free of water.
The amount of liquid carrier in the composition according to the present disclosure is from about 50 wt.% to about 99 wt.%, typically from about 75 wt.% to about 99 wt.%, still more typically from about 90 wt.% to about 99 wt.%, relative to the total amount of the composition.
The compositions described herein may be used to produce the films described herein. Suitable methods include:
(i) applying the composition described herein to a surface of a liquid that is immiscible with the liquid carrier of the composition, and
(ii) the liquid carrier of the composition is removed, thereby producing a film.
The step of applying the composition described herein to a surface of a liquid that is immiscible with the liquid carrier of the composition can be accomplished using any method known to one of ordinary skill.
The liquid that is immiscible with the liquid carrier of the composition can be any solvent or blend of solvents that is immiscible with the liquid carrier of the composition. In embodiments, the liquid immiscible with the liquid carrier of the composition is diethylene glycol.
After the coating step, the step of removing the liquid carrier of the composition can be accomplished according to any method known to one of ordinary skill. For example, the liquid carrier of the composition can be allowed to evaporate at a temperature and pressure selected by the skilled artisan according to the liquid carrier to be removed. In embodiments, the step of removing the liquid carrier of the composition is performed at ambient temperature and pressure.
The present disclosure relates to a method for adjusting the permeability of a nanoparticle comprising contacting the nanoparticle with a compound conforming to formula (I) or (II).
In an embodiment, the nanoparticles are metal oxide nanoparticles.
In an embodiment, the contacting step is ligand exchange.
The magnetic characteristics of the hybrid nanoparticles of the present invention, such as the Zero Field Cooling (ZFC) curve and relative permeability, can be determined using methods known to those of ordinary skill in the art. For example, ZFC curves can be collected on superconducting quantum interference devices (SQUIDs).
The relative permeability (μ) of the mixed nanoparticles of the invention can be measured using any known methodr). A suitable method comprises depositing material into a ring shaped sample holder and measuring the reactance and resistance of the sample at logarithmic frequency over a frequency range of 1-500MHz on a network analyzer. The values of reactance and resistance are then converted to the real part of permeability (μ'r) And imaginary part (mu) "r)，
Wherein XmIs reactance, RmIs the resistance, f is the frequency of the AC field, μ0Is the vacuum permeability, h is the height, c is the outer diameter of the annular sample and b is the inner diameter of the annular sample.
In an embodiment, the permeability of the nanoparticles is reduced.
In an embodiment, the FMR frequency is increased.
The hybrid nanoparticles, compositions, methods and processes and films according to the present disclosure are further illustrated by by the following non-limiting examples.
Examples of the invention
The materials used in the following examples are summarized below unless otherwise indicated.
Manganese (II) acetylacetonate, zinc (II) acetylacetonate, iron (III) acetylacetonate (99 +%), 1-octadecene (technical grade, 90%) were purchased from Acros Organics, Inc. Nickel (II) acetylacetonate (95%), trioctylphosphine (97%), benzyl ether (98%), oleic acid (technical, 90%) and oleylamine (technical, 70%) were purchased from Sigma Aldrich (Sigma-Aldrich). All chemicals were used as received. 2, 2-Dimethoxypropane (98 +%), bis-MPA (98%), bromopropyne (80%, solution in toluene), propargyl alcohol (99%), pyridine (reagent), Dowex H+Ion exchange resin (200-400 mesh) p-toluene sulfonic acidAcyl chloride (TsCl, 99 +%), copper (II) sulfate pentahydrate (98+), triethylamine (Et)3N, 99%) and oleylamine (80% -90%) were purchased from Acros. N, N' -dicyclohexylcarbodiimide (DCC, 99%), NaN3(≧ 99.5%), 4-dimethylaminopyridine (DMAP, 99%), stearic anhydride (> 97%), sodium L-ascorbate (> 99%) and 11-bromo-1-deca alkanol (98%) were purchased from Aldrich, Inc. (Aldrich) all chemicals as received, without further purification2Upper dry CH2Cl2And temporarily distilled before use. Adding HAuCl4·3H2O was stored in a 4 ℃ refrigerator.
12-azidododecanoic acid 5a was produced as follows. To a stirred solution of 12-bromododecanoic acid (10g, 19.2mmol) in DMF (50mL) at room temperature was added NaN3(3.74g, 57.6mmol) as part and the resulting mixture was stirred at 90 ℃ for an additional 12h, the mixture was cooled to room temperature, diluted with EtOAc (200mL) and washed with water (3X 100mL), 1N HCl (2X 100mL) and brine (50 mL.) the organic fraction was purified over Na2SO4Dried above and concentrated under reduced pressure to give pure 12-azidododecanoic acid 5a (4.4g, 95%) as a white solid.1H NMR(CDCl3)δ3.25(t,J＝7.0Hz,2H),2.34(t,J＝7.5Hz,2H),1.68-1.53(m,4H),1.39-1.24(m,14H)；13C NMR(CDCl3)δ180.39,51.62,34.20,29.56,29.49,29.33,29.26,29.16,28.96,26.84,24.78。
12-azidododecylphosphonic acid 5b was purchased from Alfa-Aesar.
generally, unless otherwise noted, recordings were made on either a Bruker UNI500 or BIODRX500 NMR spectrometer1HNMR (500MHz) and13c NMR (126MHz) spectrum.1H and13the C chemical shifts (δ) are reported in ppm, while the coupling constants (J) are reported in hertz (Hz).1The multiplicity of signals in the H NMR spectrum is described as "s" (singlet), "d" (doublet), "t" (triplet), "q" (quartet), "p" (quintet), "dd" (doublet) and "m" (multiplet). All spectra were referenced using solvent residual signal (CDCl)3：1H，δ7.27ppm；13C，δ77.2ppm，MeOD：1H，δ3.31ppm；13C, δ 49.00ppm) heteronuclear coherence using 2D bonds1H-13The C HSQC experiment confirmed the NMR peak assignments.
By thin layer chromatography on silica gel coated plates or1H NMR monitored the progress of the reaction. Filtration, precipitation, crystallization and/or flash column chromatography are carried out on silica gel as indicated (Acros Organics,35-70 μm) of purified compound.
Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry was performed on a Bruker Ultraflex III (Maldi-Tof-Tof) mass spectrometer using anthratriphenol as the matrix.
TEM micrographs were collected using a JEOL 1400 microscope operated at 120 kV. Using MAG
The Zero Field Cooling (ZFC) curve was collected by a Quantum Design MPMS-XL 7T superconducting Quantum interference device (SQUID).
Relative permeability (μ) of the hybrid nanoparticles of the inventionr) Measured by a 4395A Agilent network analyzer and 16454A Agilent magnetic material test fixture. The mixed NC dispersed in hexane was deposited into a ring-shaped sample holder (8mm outer diameter, 3.2mm inner diameter, 3mm height and 2.5mm depth) and dried. The reactance and resistance of the test fixture were measured at logarithmic frequency over the frequency range of 1-500MHz and converted to the real part of permeability (μ'r) And imaginary part (mu) "r)。
Example 1 Synthesis of a Compound conforming to formula (I) or (II).
First, intermediates 1-4 were prepared using the following strategy: late end-group functionalization with dendrimers derived from 2, 2-bis (hydroxymethyl) -propionic acid (bis-MPA) via stearic anhydride. The general reaction scheme is shown below.
Scheme S1.
Compound 1 was made according to scheme 1 below.
Scheme 1.
To propargyl alcohol 6(1g, 17.8mmol), DMAP (0.22g, 1.8mmol) and pyridine (2.8g, 35.6mmol) in CH2Cl2To a stirred solution in (50mL) was added stearic anhydride (11.8g, 21.4mmol) and the resulting mixture was stirred for 12 h. The reaction mixture was treated with additional CH2Cl2Diluted (50mL), washed with 1N HCl (3X 50mL), dried over anhydrous MgSO4Dry above, filter and concentrate the filtrate under reduced pressure. By column chromatography (SiO)20-50% EtOAc: hexanes) to afford compound 1(5.46g, 95%).1H NMR(CDCl3)δ4.67(d,J＝2.5Hz,2H),2.46(t,J＝2.5Hz,1H),2.34(t,J＝7.5Hz,2H),1.63(p,J＝7.3Hz,2H),1.33–1.23(m,28H),0.87(t,J＝6.9Hz,3H)；13CNMR(CDCl3)δ173.10,77.94,74.80,51.86,34.13,32.07,29.84,29.82,29.80,29.78,29.72,29.57,29.50,29.36,29.20,24.95,22.83,14.25。
To a stirred solution of bis-MPA (18g, 136.3mmol) in DMF (100mL) was added KOH (8.2g, 146.6 mmol). The resulting solution was stirred at 100 ℃ for 2h, after which bromopropyne (20.3g, 137mmol) was added dropwise (over 30 min) and stirring continued for an additional 48 h. The solution was cooled to 23 ℃, filtered and DMF was evaporated under reduced pressure. The residue was dissolved in chloroform (70mL), filtered and the filtrate was placed in a-10 ℃ freezer for 2 h. The resulting white precipitate was rapidly filtered and dried to give prop-2-yn-1-yl 3-hydroxy-2- (hydroxymethyl) -2-methyl as a white solidPropionate 7(13.8g, 60%).1HNMR(CDCl3)δ4.73(d,J＝2.5Hz,2H),3.88(d,J＝11.4Hz,2H),3.70(d,J＝13.1Hz,2H),3.30-2.74(m,2H),2.49(t,J＝2.4Hz,1H),1.09(s,3H)；13C NMR(CDCl3)δ175.13,77.47,75.37,67.33,52.56,49.49,17.12。
To 7, DMAP and pyridine in CH2Cl2To the stirred solution in (50mL) was added stearic anhydride and the resulting mixture was stirred for 12 h. The reaction mixture was treated with additional CH2Cl2Diluted (50mL), washed with 1N HCl (3X 50mL), dried over anhydrous MgSO4Dry above, filter and concentrate the filtrate under reduced pressure. By column chromatography (SiO)20-50% EtOAc: hexanes) to afford compound 2(2.3g, 92%). By starting from CHCl3Repeated precipitation into MeOH steps purified compound 2.1H NMR(CHCl3)δ4.68(d,J＝2.5Hz,2H),4.23(d,J＝11.0Hz,2H),4.20(d,J＝11.1Hz,2H),2.44(t,J＝2.5Hz,1H),2.27(t,J＝7.6Hz,4H),1.57(t,J＝7.3Hz,4H),1.30-1.20(m,59H),0.85(t,J＝6.9Hz,6H)；13C NMR(CDCl3)δ173.26,172.14,77.27,75.19,65.19,52.62,46.46,34.19,32.04,29.81,29.79,29.77,29.72,29.58,29.48,29.37,29.23,24.97,22.80,17.77,14.21。
To prop-2-yn-1-yl 3-hydroxy-2- (hydroxymethyl) -2-methylpropionate 7(8.0g, 46.5mmol), DMAP (2.27g, 18.6mmol) and pyridine (11.0g, 139.4mmol) in CH2Cl2(100mL) to a stirred solution was added 2,2, 5-trimethyl-1, 3-dioxane-5-carboxylic acid anhydride, 10(36.8g, 111.5mmol) and the resulting mixture was stirred for 24 h. According to published procedures (see, Ihre, h.; Hult, a.; frechet, j.m.j.; Gitsov, i.macromolecules [ macromolecules ])]1998,31, 4061; and gilles, e.r.; frechet, J.M.J.J.J.Am.chem.Soc. [ American society for chemistry]2002,124,14137) to synthesize
To a stirred solution of 2-methyl-2- ((prop-2-yn-1-yloxy) carbonyl) propane-1, 3-diylbis (2,2, 5-trimethyl-1, 3-dioxane-5-carboxylate) 8(15.0g, 31.0mmol) in MeOH was added DOWEX resin (10g) and the resulting suspension was stirred at 40 ℃ for 2h, after which,13c NMR showed the disappearance of the acetonide quaternary carbon signal (about 98 ppm). The suspension was filtered, and the filtrate was concentrated under reduced pressure to give compound 9(12.46g,>99％)。1H NMR(CDCl3)δ4.74(d,J＝2.4Hz,2H),4.45(d,J＝11.1Hz,2H),4.29(d,J＝11.2Hz,2H),3.84(dd,J＝10.3,7.6Hz,4H),3.70(dd,J＝11.4,9.9Hz,4H),2.71(s,4H),2.49(t,J＝2.4Hz,1H),1.33(s,3H),1.05(s,6H)；13CNMR(CDCl3)δ175.09,172.33,77.36,75.66,66.97,66.95,64.80,52.86,49.90,46.48,18.04,17.21；MALDI-TOF(m/z)：C18H28O10[ M + Na ] of Na]+Calculated value 427.1580; found 427.275.
To
Compound 11 was synthesized according to the procedure associated with
Compound 12 was synthesized from compound 11 under the conditions described for the conversion of compound 8 to
Compound 5a or 5b was coupled with compound 1-4 according to scheme S2 below to form compounds 13-17.
Scheme S2.
Typically, compound 5a or 5b (4.14mmol), prop-2-yn-1-yl stearate (1.33g, 4.14mmol) and CuSO are added4·5H2O (0.42g, 1.66mmol) in THF/H2To a stirred solution in 4:1(8mL) was added sodium ascorbate (0.44g, 2.22mmol) and the resulting mixture was stirred under microwave irradiation (constant temperature mode) at 65 ℃ for 6 h. The solvent was evaporated and the residue was dissolved in CHCl3(100mL) and washed with 1N HCl (
12- (4- ((stearoyl)Oxy) methyl) -1H-1,2, 3-triazol-1-yl) dodecanoic acid 13, prepared according to the general procedure. White solid (2.12g, 91%).1H NMR(CDCl3)δ7.58(s,1H),5.21(s,2H),4.33(t,J＝7.3Hz,2H),2.34(t,J＝7.5Hz,2H),2.31(t,J＝7.7Hz,2H),1.89(p,J＝7.1Hz,2H),1.67–1.56(m,4H),1.34–1.22(m,43H),0.87(t,J＝6.9Hz,3H)；13C NMR(CDCl3)δ178.97,173.99,143.06,123.70,57.63,50.56,34.30,34.03,32.07,30.37,29.84,29.82,29.80,29.75,29.60,29.51,29.45,29.41,29.39,29.26,29.25,29.11,29.05,26.55,24.99,24.81,22.84,14.27；MALDI-TOF(m/z)：C33H61N3O4[ M + Na ] of Na]+Calculated value 586.4560; found 586.528.
12- (4- (((2-methyl-3- (stearoyloxy) -2- ((stearoyloxy) methyl) propionyl) oxy) methyl) -1H-1,2, 3-triazol-1-yl) dodecanoic acid 14 was prepared according to the general procedure. White solid (0.9g, 93%).1H NMR(CDCl3)δ7.57(s,1H),5.25(s,2H),4.33(t,J＝7.4Hz,2H),4.21(q,J＝11.0Hz,4H),2.35(t,J＝7.5Hz,2H),2.24(t,J＝7.6Hz,4H),1.94–1.85(m,2H),1.63(p,J＝7.4Hz,2H),1.56(p,J＝7.4Hz,4H),1.34–1.23(m,70H),1.21(s,3H),0.87(t,J＝6.9Hz,6H)；13C NMR(CDCl3)δ178.85,173.39,172.94,142.49,123.73,77.42,77.16,76.91,65.23,58.57,50.59,46.48,34.21,34.01,32.07,30.39,29.85,29.81,29.77,29.64,29.51,29.47,29.42,29.27,29.12,29.06,26.58,24.99,24.82,22.83,17.87,14.26；MALDI-TOF(m/z)：C56H103N3O8[ M + Na ] of Na]+Calculated value 968.7643; found 969.021.
12- (4- (((2-methyl-3- (stearoyloxy) -2- ((stearoyloxy) methyl) propionyl) oxy) -2- (((2-methyl-3- (stearoyloxy) -2- ((stearoyloxy) methyl) propionyl) oxy)) Methyl) propionyl) oxy) methyl) -1H-1,2, 3-triazol-1-yl)
Compound 16. was prepared according to the general procedure. White solid (0.6g, 79%).1H NMR(CDCl3)δ7.71(s,1H),5.25(s,2H),4.36(t,J＝7.3Hz,2H),4.32-4.09(m,28H),2.34(t,J＝7.4Hz,2H),2.28(t,J＝7.6Hz,16H),1.96-1.85(m,2H),1.65-1.54(m,18H),1.33-1.22(m,241H),1.21(s,12H),1.19(s,6H),0.87(t,J＝6.8Hz,24H)；13C NMR(126MHz,CDCl3)δ178.78,173.33,172.18,172.14,171.56,66.27,65.33,65.02,58.68,50.59,46.80,46.74,46.50,34.17,33.75,32.08,30.42,29.88,29.87,29.83,29.69,29.52,29.49,29.38,29.32,29.21,29.06,26.56,25.02,24.82,22.85,17.95,17.60,14.27；MALDI-TOF(m/z)：C194H355N3O32[ M + Na ] of Na]+Calculated value 3262.6141; found 3262.661.
(11- (4- (((2-methyl-3- (stearoyloxy) -2- ((stearoyloxy) methyl) propionyl) oxy) -2- (((2-methyl-3- (stearoyloxy) -2- ((stearoyloxy) methyl) propionyl) oxy)Yl) oxy) methyl) propionyl) oxy) methyl) -1H-1,2, 3-triazol-1-yl) deca alkyl) phosphonic acid 17 was prepared according to the general procedure white solid (0.5g, 90%).1H NMR(CDCl3)δ7.72(s,1H),5.25(s,2H),4.36(t,J＝7.3Hz,2H),4.23(q,J＝11.1Hz,4H),4.14(t,J＝8.4Hz,8H),2.27(t,J＝7.5Hz,8H),1.98-1.83(m,2H),1.83-1.67(m,2H),1.57(p,J＝7.3Hz,11H),1.47-1.18(m,133H),1.17(s,6H),0.87(t,J＝6.7Hz,12H)；13C NMR(CDCl3)δ173.34,172.27,172.13,65.64,65.09,58.48,50.71,46.79,46.49,34.16,32.06,30.71,30.60,30.39,29.84,29.82,29.80,29.78,29.64,29.61,29.52,29.49,29.44,29.28,29.21,29.14,26.67,25.00,22.82,22.24,17.89,17.65,14.24；MALDI-TOF(m/z)：C102H190N3O17[ M + Na ] of Na]+Calculated value 1783.3731; found 1783.696.
Example 2. production of mixed nanoparticles of the invention.
Nickel nanocrystals were prepared as follows. 1mmol of nickel (II) acetylacetonate was dissolved in 15mL of benzyl ether together with 30mmol of oleylamine. The mixture was evacuated at room temperature for 5 minutes before injection of 30mmol trioctylphosphine. The reaction mixture was heated to 80 ℃ and held under vacuum for 30 minutes. Then, the temperature was increased to 230 ℃ at a rate of 10 ℃/min. After 30 minutes, the reaction mixture was cooled to room temperature and Ni NC was precipitated by addition of acetone. Ni NC was redispersed in toluene and washed three times with acetone.
Preparation of 11-nm Mn0.08Zn0.33Fe2.59O4NC. manganese (II) acetylacetonate 3mmol, zinc (II) acetylacetonate 6mmol, iron (III) acetylacetonate 12mmol, oleic acid 100mmol, oleylamine 112mmol and 1-octadecene 72mL were mixed in a 250mL flask the reaction mixture was heated to 110 ℃ and held under vacuum for two hours then, after increasing the temperature to 300 ℃ at a rate of 11 ℃/min two hours, the reaction mixture was cooled to room temperature and the resulting NC. manganese zinc ferrite NC was redispersed in hexane and washed three times with isopropanol steps.
Ligand exchange of Ni NC was performed using any of 10mg of compounds 13-16 dissolved in 5mL chloroform added to 1mL of Ni NC in toluene (10 mg/mL.) the reaction was stirred at room temperature for 30 minutes and stopped by precipitating the Ni NC with acetone.
Mn0.08Zn0.33Fe2.59O4Ligand exchange of NC was performed as follows. First, 150mg of compound 17 was dissolved in 5mL of hexane at 40 ℃. When the solution became clear and colorless, 150mg NC in 5mL hexane was added to the solution with compound 17 and kept at 40 ℃. After stirring overnight, 30mL of isopropanol was added to the solution to precipitate the ligand-exchanged NC. The precipitate was redispersed in 5mL of hexane. Then, 20mL of isopropanol was added again to the NC solution to remove any excess compound. The final product was dissolved and stored in hexane.
Example 3 characterization of Ni Mixed nanoparticles
The inventive mixed Ni NC produced in example 2 was drop cast and analyzed by Transmission Electron Microscopy (TEM). Fig. 2 shows TEM images of monolayers of as-synthesized Ni NC and dendrimer coated Ni NC demonstrating increased interparticle separation with algebraic change.
The data for interparticle spacing inferred from TEM images show a non-linear relationship between the molecular weight (Mw) of dendrimers, compounds 13-16, and the observed interparticle distance. G0 for compound 13, G1 for compound 14, G2 for
This observation is in contrast to pure dendrimers1The H NMR data agree very well. FIG. 3 shows a CDCl3The coverage of NMR spectra obtained for free dendrimers in solution and allows to follow the evolution of a specific signal as a function of algebraic changes. The signals of the core part (signals f, g, e and d in FIG. 3) are algebraically variedProgressively becoming wider. This is especially clear in G2 and G3, indicating reduced internal conformational mobility, which is an indication of the formation of dense, three-dimensional, spherical structures. Notably, the effect starts as low as G2, which means that a smaller number of synthetic steps are required to obtain a molecule with the optimal geometry in the series.
EXAMPLE 4 characterization of MZF hybrid nanoparticles
In Mn0.08Zn0.33Fe2.59O4In the case of NC nanocrystals, compounds 13-16 were found to result in an equilibrium between the surface bound ligand (e.g., oleic acid) and the incoming dendrimer. Under the test conditions, only a small fraction of the oleic acid was exchanged with the dendrites, as evidenced by a much smaller final interparticle separation than that observed in Ni NCs using the same ligands. This is probably due to the similar binding strength of the carboxylic acid head groups present in both oleic acid and the dendrimer, leading to equilibrium prior to the exchange of most of the ligands present.
However, it was found that compound 17, similar to
Figure 4 shows TEM images of MZF NCs before and after ligand exchange showing a significant, controlled increase in interparticle distance compared to surface-capped commercial ligands (i.e. oleic acid) by which these MZF NCs were synthesized. As can be observed in the low magnification image (fig. 4a) and the high magnification image (fig. 4b), NC is highly monodisperse with a standard deviation of only 3.7%. It is clearly observed from the selected area electron diffraction pattern (inset in fig. 4a) that NC has a spinel crystal structure. The average interparticle distance prior to ligand exchange was 2.5nm with a standard deviation of 15.7%, as measured from TEM data of drop cast solutions. In fig. 4c and 4d, TEM images at high and low magnification, respectively, after ligand exchange of MZF NC with compound 17 are shown. Clearly, the interparticle distance is extended after ligand exchange. As inferred from the TEM images, the mean interparticle distance has now become 5.0nm (with a standard deviation of 23.1%), which means that the interparticle distance has increased by a factor of two. Figure 5 shows the distribution of interparticle distances before and after ligand exchange.
Example 5 magnetic Properties of MZF hybrid nanoparticles
In FIG. 6, the return -normalized Zero Field Cooling (ZFC) curves of MZF NC before (squares) and after (circles) ligand exchange are shownB) Assigned as the maximum point of the ZFC curve and after ligand exchange with Compound 17, TBA substantial decrease from 114K to 75K indicates a reduced dipole interaction between MZFNCs. Due to the increased inter-particle distance, the dipole-dipole interaction between NCs is reduced and thus the energy barrier for thermally induced spin reorientation is reduced, resulting in a lower TB。
For the dynamic magnetic properties of NC, the relative permeability μr＝μ′r-jμ″rTo examine the AC permeability (μ). In this study, the relative permeability (. mu.) in the frequency range of 10-500MHzr) From a measurement-based model of a single turn inductor. In FIG. 7a, the real part of the relative permeability (μ'r) From 10 to 2, which is mainly attributable to ligand exchange resulting in a significant reduction in the volume fraction of NC in the dry powder samples. Thus, the magnetic field flux density in the NC sample after ligand exchange becomes smaller, which is exhibited at reduced μ'rIn (1). However, it is noteworthy μ 'of NC with Compound 17'rThe value is more than the value of NC as a synthetic material, such as μ 'which can be classified into 'r(μ′r/μ′r initial) Observed in the graph (shown in FIG. 8), where μ'r initialIs mu 'at 10 MHz'rFor example, μ 'to at 500MHz for Synthesis-as-synthesized NC and ligand-exchanged NC'rThe values are 0.29 and 0.76, respectively. For the imaginary part (mu') of the relative permeabilityr) Superparamagnetic-ferromagnetic relaxation frequency versus frequency (ω)Maximum value) Wherein μ ″)rValue reaches maximumThe value is obtained. The μ "value of MZF NC reached a maximum at 45MHz frequency prior to ligand exchange. In contrast, μ ″, after ligand exchangerThe values show a slight increase, with no maximum up to 500MHz, indicating ωMaximum valueHigher than 500 MHz. OmegaMaximum valueIncrease in (f) corresponds to a shorter neel relaxation time (τ)N＝1/ωMaximum value) Which is the result of the reduced dipole-dipole interaction brought about by the ligand exchange process. Increased omegaMaximum valueIndicating that the operable frequency range of the NC is expanded to higher frequencies, which supports the suitability of our method for using the NC in AC magnetics. Mu ″)rThe significant reduction in (d) causes a large change in the energy efficiency of the material, which is examined by the loss tangent (tan δ). After ligand exchange, the MZF NC showed much lower loss tangent values over the entire measuring frequency range (fig. 7 c). That is, the increased interparticle distance induces lower dipole-dipole interactions, making the magnetic moment of the dendrite coated NC more coherent with external magnetic fields than the magnetic moment of the synthetic-like NC. Since the loss tangent is defined as the ratio of the imaginary part to the real part of the permeability, this result means μ ″)rIs reduced by: 'mu'rThe effect of inter-particle spacing on the AC magnetic properties of MZFNCs at radio frequency will need to be further optimization of ligand-exchanged NC to achieve a higher real part of permeability for magnetic applications.
As described herein, a significant reduction in μ 'may be achieved using the compounds conforming to formula (I) or (II) of the present invention'r、μ″rImportantly, the FMR frequency of the NC increases from 45MHz to over 500MHz, indicating the potential of the method to utilize the NC at radio frequencies.
Example 6 thermal behaviour of the compound according to formula (I) or (II).
The thermal behaviour of the compounds according to formula (I) or (II) according to the invention was investigated by Differential Scanning Calorimetry (DSC). Figures 9a-9e show DSC traces for compounds 13-17 of example 1, respectively. DSC curves provide information about the behavior of the individual compounds upon melting or solidification and the thermal state each compound undergoes. "Cr" refers to a crystalline phase and "Iso" refers to an isotropic liquid.
DSC analyses are summarized in table 1 below.
TABLE 1 DSC analysis of compounds 13-17.
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