Sandwich type isopolytungstate and preparation method thereof
阅读说明：本技术 一种夹心型的同多钨酸盐及其制备方法 (Sandwich type isopolytungstate and preparation method thereof ) 是由 张超 张红端 申莉娟 于 2021-06-03 设计创作，主要内容包括：本发明提供一种新型的杠铃状夹心型同多钨酸盐及其制备方法。该夹心型同多钨酸盐{Na-(8)H-(10)[Mn～(III)-(4)O-(4)(HW-(9)O-(33))-(2)]·17H-(2)O}是中心对称结构的一维链状的夹心型化合物,其中的聚阴离子[Mn～(III)-(4)O-(4)(HW-(9)O-(33))-(2)]～(18-)由两个{W-(9)}亚单元和夹心层{Mn-(4)}簇构成。夹心层{Mn-(4)}簇中的{MnO-(6)}八面体之间通过共边的方式连接,{W-(9)}亚单元包括3个以共点的方式相连{W-(3)}三金属簇,其中每个三金属簇{W-(3)}之间以共边的方式连接一体,每个{W-(9)}亚单元由以Mn-O-W键和夹心层{Mn-(4)}簇联结完整,形成杠铃型结构。该杠铃状夹心型同多钨酸盐具有优异的光学性质,对红外和紫外光谱敏感。(The invention provides a novel barbell-shaped sandwich isopolytungstate and a preparation method thereof. The sandwich isopolytungstate { Na } 8 H 10 [Mn III 4 O 4 (HW 9 O 33 ) 2 ]·17H 2 O is a one-dimensional chain sandwich type compound with a centrosymmetric structure, wherein polyanion [ Mn ] is III 4 O 4 (HW 9 O 33 ) 2 ] 18‑ From two { W 9 Subunit and sandwich layer { Mn } 4 And (5) cluster construction. Sandwich layer { Mn 4 { MnO in } Cluster 6 The octahedrons are connected in a common edge mode, and W 9 The subunit comprises 3 connected in a common point manner { W } 3 Triple metal clusters, wherein each triple metal cluster { W } 3 Are connected into a whole in a common edge mode, and each { W } 9 The subunit consists of Mn-O-W bonds and a sandwich layer { Mn } 4 The clusters are completely connected to form a barbell-shaped structure. The barbell-shaped sandwich isopolytungstate has excellent optical properties, and can be used for infrared and ultravioletAnd (4) spectrum sensitivity.)
1. A polytungstate with a molecular formula of { Na8H10[MnIII 4O4(HW9O33)2]·17H2O }, which is characterized in that the poly tungstate is sandwich type isopolytungstate and has a barbell-shaped structure.
2. The polytungstate of claim 1, wherein { Na }8H10[MnIII 4O4(HW9O33)2]·17H2The valences of Mn atoms in O atoms are all +3 valences, and the valences of W atoms are all +6 valences.
3. The polytungstate of claim 1, wherein { Na }8H10[MnIII 4O4(HW9O33)2]·17H2Polyanion [ Mn ] in O ]III 4O4(HW9O33)2]18-From two { W9Subunit and sandwich layer { Mn }4And (5) cluster construction. Sandwich layer { Mn4{ MnO in } Cluster6The octahedrons are connected in a common edge mode, and W9The subunit comprises 3 connected in a common point manner { W }3Triple metal clusters, wherein each triple metal cluster { W }3Are connected into a whole in a common edge mode, and each { W }9The subunit consists of Mn-O-W bonds and a sandwich layer { Mn }4The cluster is completely connected to form a barbell-shaped structure; each polyanion passing Na+And (4) ion connection to form a one-dimensional chain-shaped sandwich type manganese oxide cluster compound.
4. Polytungstate according to claim 3, characterized in that the polyanion [ Mn ]III 4O4(HW9O33)2]18-Including 6 triple bridge oxygens (O1, O2, O3, O4, O6 and O16), 19 double bridge oxygens (O9, O12, O14, etc.) and 9 terminal oxygens (O29, O31, O33, etc.), each Mn atom in the polyanion is { MnO6Octahedron, the bond length range of Mn-O isAll W atoms are { WO6Octahedron, the bond length of the W-O bridge oxygen bond is in the rangeW-OdThe range of the terminal oxygen bond is
5. The polytungstate of claim 3, wherein { Na ™ is8H10[MnIII 4O4(HW9O33)2]·17H2Sandwich layer of O is Mn4Cluster, containing no W atom.
6. A preparation method of poly tungstate comprises the following steps,
step 1, adding manganese acetate Mn (CH)3COO)2·4H2O is completely dissolved in acetic acid (CH)3COOH), adding a proper amount of KMnO4Then continuously stirring to obtain purple black MnIII 8MnIV 4O12(CH3COO)16(H2O)4]A solution;
step 2, [ MnIII 8MnIV 4O12(CH3COO)16(H2O)4]The solution is mixed with Na2WO42H2O reacting for a certain time, adding Mn (CH)3COO)2·4H2And O, heating and continuously stirring, cooling, filtering and standing until dark brown needle crystals grow out of the solution.
7. The method as claimed in claim 6, wherein step 1 is carried out by adding manganese acetate Mn (CH)3COO)2·4H2O (4.000g, 16.32mmol) was dissolved in 40mL of 60% volume fraction acetic acid (CH)3COOH), after completely dissolving, KMnO is added4(1g, 6.32mmol) followed by stirring for a further 1h, which will finally give a purplish black color of [ MnIII 8MnIV 4O12(CH3COO)16(H2O)4]And (3) solution.
8. The method of claim 6, wherein step 2 is carried out by mixing [ MnIII 8MnIV 4O12(CH3COO)16(H2O)4]Mixing the solution with Na2WO4 & 2H2O, reacting for 30S-50S, and adding a certain amount of Mn (CH)3COO)2·4H2And O. Heating to 90 deg.C and stirring for 1 hr, cooling to room temperature, and filtering to obtain clear liquid; after 2 to 3 days, dark brown needle-like crystals grew out of the solution.
Technical Field
The invention relates to the technical field of polyoxometallate, in particular to sandwich isopolytungstate and a preparation method thereof.
Background
Polyoxometalates (polyacid) is the pre-transition metal in the highest oxidation state (V)5 +、Nb5+、W6+Etc.) discrete metal-oxyanions formed in combination with oxygen, the MOs generally joined together in a common angle, edge, or plane6Octahedral units are connected.
In recent years, the polyacid has been widely noticed by the academic community because of its attractive properties represented by its unique structure, and has potential application value in the fields of antitumor drugs, solar cells, functional catalysts, LB membranes and the like.
The sandwich type polyacid consists of two polyacid fragments and a transition metal cluster, and shows better properties in the fields of electricity, magnetism, optics and the like. The structure determines the properties and the performance of the material, so that the discovery of sandwich polyacids with novel structures is of great importance.
Disclosure of Invention
In view of the above problems, the present invention is to provide a novel barbell-shaped sandwich isopolytungstate and a method for preparing the same.
A polytungstate with a molecular formula of { Na8H10[MnIII 4O4(HW9O33)2]·17H2O }, which is characterized in that the poly tungstate is sandwich type isopolytungstate and has a barbell-shaped structure.
{Na8H10[MnIII 4O4(HW9O33)2]·17H2The valences of Mn atoms in O atoms are all +3 valences, and the valences of W atoms are all +6 valences.
The { Na8H10[MnIII 4O4(HW9O33)2]·17H2Polyanion [ Mn ] in O ]III 4O4(HW9O33)2]18-From two { W9Subunit and sandwich layer { Mn }4And (5) cluster construction. Sandwich layer { Mn4{ MnO in } Cluster6The octahedrons are connected in a common edge mode, and W9The subunit comprises 3 connected in a common point manner { W }3Triple metal clusters, wherein each triple metal cluster { W }3Are connected into a whole in a common edge mode, and each { W }9The subunit consists of Mn-O-W bonds and a sandwich layer { Mn }4The clusters are completely connected to form a barbell-shaped structure. Each polyanion passing Na+And (4) ion connection to form a one-dimensional chain-shaped sandwich type manganese oxide cluster compound.
Said polyanion [ MnIII 4O4(HW9O33)2]18-Including 6 triple bridge oxygens (O1, O2, O3, O4, O6 and O16), 19 double bridge oxygens (O9, O12, O14, etc.) and 9 terminal oxygens (O29, O31, O33, etc.), each Mn atom in the polyanion is { MnO6Octahedron, the bond length range of Mn-O isAll W atoms are { WO6Octahedron, the bond length of the W-O bridge oxygen bond is in the rangeW-OdThe range of the terminal oxygen bond is
The { Na8H10[MnIII 4O4(HW9O33)2]·17H2Sandwich layer of O is Mn4Cluster, containing no W atom.
A preparation method of poly tungstate comprises the following steps:
step 1, adding manganese acetate Mn (CH)3COO)2·4H2O is completely dissolved in acetic acid (CH)3COOH), adding a proper amount of KMnO4Then continuously stirring to obtain purple black MnIII 8MnIV 4O12(CH3COO)16(H2O)4]And (3) solution.
Step 2, [ MnIII 8MnIV 4O12(CH3COO)16(H2O)4]Mixing the solution with Na2WO4 & 2H2O, reacting for a certain time, and adding a proper amount of Mn (CH)3COO)2·4H2O, heating and continuously stirring, cooling, filtering, and standing until deep brown grows out in the solutionColored needle-like crystals.
The invention has the beneficial effects that:
the invention provides a novel barbell-shaped sandwich isopolytungstate and a preparation method thereof. The sandwich isopolytungstate { Na }8H10[MnIII 4O4(HW9O33)2]·17H2O is a one-dimensional chain sandwich type compound with a centrosymmetric structure, wherein polyanion [ Mn ] isIII 4O4(HW9O33)2]18-From two { W9Subunit and sandwich layer { Mn }4And (5) cluster construction. Sandwich layer { Mn4{ MnO in } Cluster6The octahedrons are connected in a common edge mode, and W9The subunit comprises 3 connected in a common point manner { W }3Triple metal clusters, wherein each triple metal cluster { W }3Are connected into a whole in a common edge mode, and each { W }9The subunit consists of Mn-O-W bonds and a sandwich layer { Mn }4The clusters are completely connected to form a barbell-shaped structure. The barbell-shaped sandwich isopolytungstate has excellent optical properties and is sensitive to infrared and ultraviolet spectrums.
Drawings
The figures further illustrate the invention, but the examples in the figures do not constitute any limitation of the invention.
FIG. 1 shows a polyanion [ Mn ] according to an embodiment of the present inventionIII 4O4(HW9O33)2]18-From two { W9Subunit and sandwich layer { Mn }4A is a polyhedral structure diagram of polyanion of compound 1, and b is a ball stick diagram of polyanion structure of compound 1.
Fig. 2 is a structural diagram of a one-dimensional chain-like sandwich-type manganese oxide cluster compound according to an embodiment of the present invention.
FIG. 3 shows [ Mn ] according to an embodiment of the present inventionIII 4O4(HW9O33)2]18-Polyanion structure, a is { W }9B is a sandwich layer { Mn }4And (4) clusters.
FIG. 4 shows an embodiment of the present invention providing a compound { Na8H10[MnIII 4O4(HW9O33)2]·17H2O } infrared spectrum.
FIG. 5 shows an embodiment of the present invention providing a compound { Na8H10[MnIII 4O4(HW9O33)2]·17H2O } of
Detailed Description
A polytungstate with a molecular formula of { Na8H10[MnIII 4O4(HW9O33)2]·17H2O }, which is characterized in that the poly tungstate is sandwich type isopolytungstate and has a barbell-shaped structure.
X-ray single crystal diffraction results show that8H10[MnIII 4O4(HW9O33)2]·17H2O } contains 1 [ MnIII 4O4(HW9O33)2]18-Polyanion, 8 Na+Ion, 10H+Ions and 17 crystal waters, and polyanion [ MnIII 4O4(HW9O33)2]18-From two { W9Subunit and sandwich layer { Mn }4Cluster formation as shown in fig. 1. { MnO in Sandwich layer6The octahedrons are connected in a common edge mode, and W9The subunit comprises 3 connected in a common point manner { W }3Triple metal clusters, wherein each triple metal cluster { W }3Are connected into a whole in a common edge mode, and each { W }9The subunit consists of Mn-O-W bonds and a sandwich layer { Mn }4Cluster bonds were complete so that the entirety of compound 1 looked like 1 barbell. Finally each polyanion is passed over Na+The ionic connection is an example of a classic one-dimensional chain sandwich type manganese oxide cluster compound, as shown in figure 2. Wherein [ Mn ]III 4O4(HW9O33)2]18-Of polyanionsThe structure is shown in figure 3.
{Na8H10[MnIII 4O4(HW9O33)2]·17H2Polyanion of O [ Mn ]III 4O4(HW9O33)2]18-Including 6 triple bridge oxygens (O1, O2, O3, O4, O6 and O16), 19 double bridge oxygens (O9, O12, O14, etc.) and 9 terminal oxygens (O29, O31, O33, etc.), each Mn atom in the polyanion is { MnO6Octahedron, the bond length range of Mn-O is All W atoms are { WO6Octahedron, the bond length of the W-O bridge oxygen bond is in the rangeThe W-Od terminal oxygen bond has a range of
{Na8H10[MnIII 4O4(HW9O33)2]·17H2O { W }9The subunit can be regarded as a-Keggin-like structure metatungstate anion [ H ]3W12O40]5-Losing any group of three metal clusters { W3O13Get, without heteroatoms located in the central cavities of the four trimetallic clusters, and coordinate only 1 proton on the oxygen inside the subunit. { Na8H10[MnIII 4O4(HW9O33)2]·17H2O } is a sandwich layer of a sandwich type structure of { Mn4Cluster without W atom.
A preparation method of poly tungstate comprises the following steps:
step 1, adding manganese acetate Mn (CH)3COO)2·4H2O (4.000g, 16.32mmol) was dissolved in 40mL of 60% volume fraction acetic acid (CH)3COOH), after completely dissolving, KMnO is added4(1g, 6.32mmol) followed by stirring for a further 1h, which will finally give a purplish black color of [ MnIII 8MnIV 4O12(CH3COO)16(H2O)4]And (3) solution.
Step 2, [ Mn ]III 8MnIV 4O12(CH3COO)16(H2O)4]Mixing the solution with Na2WO4 & 2H2O, reacting for 30S-50S, and adding a certain amount of Mn (CH)3COO)2·4H2And O. After heating to 90 ℃ and continued stirring for 1h, cooling to room temperature and filtering off the clear solution. After 2 to 3 days, dark brown needle-like crystals grew out of the solution.
Intact { Na is selected with the size of 0.17mm multiplied by 0.14mm multiplied by 0.12mm8H10[MnIII 4O4(HW9O33)2]·17H2O } crystal was placed on a Bruker Apex-II CCD diffractometer with Mo target K passing through a graphite monochromatorαThe radiation is used as a radiation source, radiation data is scanned in an omega-2 theta mode, 67004 diffraction points are collected at 150.0K in total, and 12066(R is the independent diffraction point)int0.0732). According to the results of X-ray single crystal diffraction, { Na8H10[MnIII 4O4(HW9O33)2]·17H2O } belongs to the monoclinic system, P21Space group, { Na }8H10[MnIII 4O4(HW9O33)2]·17H2Crystallographic data of O } are shown in table 1 below.
Table 1 Compounds { Na8H10[MnIII 4O4(HW9O33)2]·17H2Crystallographic data of O
From the valence calculation results, we found that the compound { Na8H10[MnIII 4O4(HW9O33)2]·17H2BVS calculation results of Mn atoms of O } were all between 3.03 and 3.37, so the valence of Mn atoms was all +3, and BVS calculation results of all W atoms were between 5.99 and 6.26, so the valence of W atoms was all +6, and the valence bond calculation results of O, Mn and W atoms in polyanion of compound 1 are shown in table 2.
TABLE 2 Compounds { Na8H10[MnIII 4O4(HW9O33)2]·17H2Calculation of the valence bond between O, Mn and W atom in O } anion
For compound { Na8H10[MnIII 4O4(HW9O33)2]·17H2O } infrared spectroscopic analysis at 1000cm-1The characteristic absorption peaks at the latter several positions are 936cm respectively-1、874cm-1And 736cm-1Are respectively assigned to v (W-O)1) Stretching vibration, v (W-O-W) stretching vibration and v (W-O)cW) as shown in FIG. 4.
For compound { Na8H10[MnIII 4O4(HW9O33)2]17H2O for UV-Vis Spectroscopy, FIG. 5, Compound { Na }8H10[MnIII 4O4(HW9O33)2]17H2O } shows a characteristic absorption peak at 254nm, which is expressed as Ob，cLoad transfer of → W.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solutions of the present application and not to limit them; although the present application has been described in detail with reference to preferred embodiments, those of ordinary skill in the art will understand that: modifications to the embodiments of the present application or equivalent replacements of some technical features may still be made, which should all be covered by the scope of the technical solution claimed in the present application.
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