Hydrothermal Synthesis and Crystal Structure of a Keggin Polyoxometalate [Co^Ⅱ（2,2′-bipy）2（H2O）]2[SiW^Ⅵ12O40]·2H2O

A Keggin-type tungstosilicate compound [Co^Ⅱ（2,2′-bipy）2（H2O）]2[SiW^Ⅵ12O40]·2H2O 1 （bipy = bipyridine） was prepared by a hydrothermal method for the first time. Single-crystal X-ray diffraction revealed that 1 （C40H40Co2N8O44SiW12） crystallizes in the triclinic system, space group P1 with a = 10.4979（6）, b = 13.3946（7）, c = 13.5756（8）A, α= 70.0769（18）, β = 68.910（3）, γ = 74.186（4）°, V = 1649.84（16）A^3, Mr = 3688.95, Z = 1, Dc = 3.713 mg·m^-3, μ = 21.432 mm^-1, F（000） = 1644, S = 1.058, the final R = 0.0511 and wR =0.1023 for 6523 observed reflections （I 〉 2σ（I））. Compound 1 consists of two coordinated cation fragments [Co^Ⅱ（2,2′-bipy）2（H2O）]^2＋, one normal Keggin polyanion unit [SiW^Ⅵ12O40]^4- and two lattice water molecules. To be noted, each polyanion unit is linked to two cation fragments by its two surface terminal oxygen atoms and two cobalt atoms of two cation fragments forming an organic-inorganic hybrid unit in 1. Furthermore, the compound shows strong photoluminescence property in the solid state at room temperature.     

Hybrid Tungstocuprate [ Cu（2,2＇-bpy）3]2 H4 [ CuW12O40 ]· 6H2O Based on Keggin Polyoxoanion [CuW12O40]^6- with Cu^Ⅱ as Heteroatom

A novel hybrid tungstocuprate （ Ⅱ ） [ Cu （2,2＇-bpy） 3 ] 2 H4 [ CuW12O40 ] · 6H2O （ 2,2＇-bpy = 2,2＇-bipyfidine） was synthesized via hydrothermal method and characterized using elemental analyses, IR, UV, XPS, TG-DSC, EPR, and X-ray single crystal diffraction. The structural analysis shows that the complex consists of an unusual Keggin-type polyoxoanion [ CuW12O40 ]^6- and a pair of chiral complex cations [ Cu（2,2＇-bpy） 3 ]^＋ together with four protons and six crystallization water molecules, and the Keggin polyoxoanion is connected with [ Cu （2,2＇-bpy）3 ]^＋v/a multiple C-H…O hydrogen bonds resulting in a dimer.     

Hydrothermal Synthesis and Structure of One New Vanadoarsenate [Zn（dien）（Hdien）]2[As6V15O42（H2O）]·4H2O

One new arsenic-vanadium cluster, [Zn（dien）（Hdien）]2[As6V15O42（H2O）]·4H2O （1, dien = diethylenetriamine）, has been hydrothermally synthesized and characterized by IR, elemental analysis, TGA, magnetic property and single-crystal X-ray diffraction analysis. Crystal data for 1： monoclinic, space group P21/n, a = 13.959（3）, b = 22.428（5）, c = 22.831（5） A^°, β = 90.733（4）°, Z = 4. X-ray crystallographic study showed that compound 1 is constructed from [As6V15O42（H2O）]^6- polyoxoanions linked together by novel [Zn（dien）（Hdien）]^3＋ complex fragments via hydrogen bonds into a three-dimensional network. Variable temperature susceptibility measurement demonstrates the presence of antiferromagnetic interaction between V^IV cations in 1.     

Hydrothermal Synthesis and Crystal Structure of a New Polyoxovanadate： [Mn（en）3]2en0.5[HV8VV8IVO38（CI）]·4.5H2O （en = Ethylenediamine）

A new compound has been synthesized under hydrothermal conditions and characterized by IR, elemental analysis, XPS and single-crystal X-ray diffraction analysis. The title compound [Mn（en）3]2en0.5[HV8VV8IVO38（CI）]·4.5H2O crystallizes in monoclinic, space group C2/c, with a = 17.016（4）, b = 18.858（4）, c = 18.872（4） A, β = 93.667（4）°, V = 6043（2）A3, Z = 4, Dc = 2.242 g/cm3, Mr = 2040.12, F（000） = 4020,μ = 2.895 mm-1, Rint = 0.0921, R = 0.0649 and wR = 0.1325. Single-crystal X-ray structure analysis indicates that the title compound consists of a polyanion [HV8VV8IVO38（CI）]4- cage, two [Mn（en）3]2^2＋ cations, four and a half lattice waters and a half ethylenediamine. In addition, intermolecular O-H...N, O-H...O, N-H...O and C-H...O hydrogen bonds link the molecules together to form a three-dimensional structure.     

Synthesis,Crystal structure and Luminescent Property of a New 3D Supramolecular Compound （C6H6NO2）3（C6H5NO2）（PW12O40）·2H2O

A supramolecular compound （C6H6NO2）3（C6H5NO2）（PW12O40）·2H2O including the Keggin-type [PW1O40]3- polyanion, [HC6H5NO2]＋ （protonated pyridine-4-carboxylic acid molecule）, C6H5NO2 （pyridine-4-carboxylic acid molecule） and two free H20 molecules has been synthesized by the hydrothermal method and characterized by elemental analysis, IR spectra, single-crystal X-ray diffraction and powder X-ray diffraction. The crystal belongs to orthorhombic, space group Pnnm with a = 1.0483（3）, b = 1.4368（6）, c = 2.0526（7） nm, V= 3.0918（18） nm3,Z = 2, F（000） = 3004, Mr= 3406.07, Dc= 1.757 g.m-3,μ = 41.241 mm-1, the final R = 0.0387 and wR = 0.1089 for 2091 observed reflections withI〉 2σ（I）. A total of 30431 reflections were collected, of which 3083 were independent （Rint = 0.0605）. S is 1.182. The title compound presents a 3-D structure via intermolecular hydrogen bonds among [PW12O40]3- polyanions and pyridine-4-carboxylic acid ligands. The ultraviolet and luminescence spectra have been studied at room temperature, of which the purple fluorescent emission is located at 363 nm when excited at 264 nm. Fluorescent emission of the compound derives from the π-π＊ transitions in the pyridine-4-carboxylic acid ligands.     

Synthesis and Crystal Structure of a Three-dimensional Manganese（Ⅱ） Complex （tataH）2[Mn（pydc）2]·4H2O （tata = 2,4,6-Trlamino-1,3,5-trlazine,pydcH2 =Pyridine-2,6-dicarboxylic Acid）

A manganese（Ⅱ） complex （tataH）2[Mn（pydc）2]·4H2O （C20H28MBN14O12, Mr = 711.50, tata = 2,4,6-triamino-1,3,5-triazine, pydcH2 = pyridine-2,6-dicarboxylic acid） has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1^-, with a = 9.9847（3）, b = 10.9813（3）, c = 15.2616（5）A, a = 101.5310（10）, β = 90.2610（10）, γ = 116.4600（ 10）% V = 1459.44（8）A^3, Z = 2, Dc = 1.619 g/cm^3,μ = 0.539 mm^-1, F（000） = 734, the final R = 0.0292 and wR = 0.0745. In the crystal the Mnn atom is six-coordinated by four carbonyl oxygen atoms and two pyridine nitrogen atoms from two tridentate pydc ligands to furnish a distorted octahedral geometry. The complex shows the A…D…D＇…A＇ H-bonded tetramer. The molecules are packed in a three-dimensional framework structure by the combination of O-H…O, N-H…O and N-H…N hydrogen bonds between （tataH）^＋, [Mn（pydc）2]^2- and crystal water.     

Synthesis and Crystal Structure of a New Mixed-ligand Cluster [Mo3O4（C2O4）2bipy-（H2O）3]·EtOH·2H2O（bipy = 2,2′-Bipyridine）

The novel mixed-ligand neutral compound [Mo3O4（C2O4）2bipy-（H2O）3]·EtOH·2H2O（bipy = 2,2′-bipyridine） has been prepared by the reaction of oxalic acid elution of Mo（IV） and bipy, and characterized by single-crystal X-ray diffraction analysis and IR. The crystal is of triclinic, space groups P1^- with a = 9.5520（2）, b = 10.3730（1）, c = 13.5722（2）A, a = 74.940（12）,β = 80.772（14）,γ= 69.898（11）°, V = 1215.73（11）A^3, Z = 2, C16H24Mo3N2O18, Mr = 820.19, Dc = 2.241 g/cm^3,μ = 1.616 mm^-1, F（000） = 808, T = 293（2） K, the final R = 0.0424 and wR = 0.0939 for 4119 observed reflections with I 〉 2σ（I）. The trinuclear unit is coordinated by mixed ligands of oxalate and bipy. The intermolecular hydrogen bonding interactions among adjacent [Mo3O4（C2O4）2·bipy（H2O）3] extend the compound into a three-dimensional supramolecular framework. The uncoordinated water molecules and ethal molecules act as space-fillers and consolidate the whole architecture through hydrogen bonding interactions.     

Hydrothermal Synthesis and Crystal Structure of a Keggin Polyoxometalate [CoⅡ(2,2'-bipy)2(H2O)]2[SiWVI12O40]·2H2O

A Keggin-type tungstosilicate compound [CoII(2,2'-bipy)2(H2O)]2[SiWVI12O40]·2H2O1 (bipy = bipyridine) was prepared by a hydrothermal method for the first time. Single-crystal X-ray diffraction revealed that 1 (C4H40Co2N8O44SiW12) crystallizes in the triclinic system, space group P1 with a = 10.4979(6), b = 13.3946(7), c = 13.5756(8) (A°), α= 70.0769(18), β= 68.910(3), y = 74.186(4)°,V =1649.84(16) (A°)3, M, = 3688.95, Z =1, Dc= 3.713 mg.m-3,μ= 21.432 mm-1, F(000) = 1644, S =1.058, the final R = 0.0511 and wR = 0.1023 for 6523 observed reflections (I> 2σ(I)). Compound 1 consists of two coordinated cation fragments [CoII(2,2'-bipy)2(H2O)]2+, one normal Keggin polyanion unit [SiWVI12O40]4- and two lattice water molecules. To be noted, each polyanion unit is linked to two cation fragments by its two surface terminal oxygen atoms and two cobalt atoms of two cation fragments forming an organic-inorganic hybrid unit in 1. Furthermore, the compound shows strong photo-luminescence property in the solid state at room temperature.     

Hydrothermal Synthesis and Characterization of a Two-dimensional Layer Based on Keggin POM Cluster Units： [Cu2（DMPz）2PMo12O40]＇HDMPz

The title compound, [Cu2（DMPz）2PMo12O40]·HDMPz （1, DMPz = 2,5-dimethyl pyrazine）, has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1 with a = 11.075（2）, b = 11.551（2）, c = 11.886（2） A.α = 106.352（2）, β = 109.862（3）, γ = 109.504（1）°, V = 1206.8（3） A3, C18H26CU2Mo12N6O40P, Mr = 2275.78, Z = 1, Dc = 3.131 g/cm3, μ = 4.011 mm^-1, F（000） = 1073, S = 1.066, the final R = 0.0389 and wR = 0.1056 for 3739 observed reflections with I 〉 2σ（I）. The structural analysis indicates that the title compound is composed of Keggin clusters [PMo12O40]3- connected by one-dimensional [CB（DMPz）]2n^2n＋ chains to form a two-dimensional grid layer with holes occupied by monoprotonated DMPz molecules. In the solid of the title compound, the 2D grid layers are stacked together in an ABAB packing mode.     

Hydrothermal Synthesis and Crystal Structure of a Polyoxometalate- based Complex [Cu^I（phen）2]4（SiW12O40）

A new hybrid polyoxometalate-based complex, [Cu^I（phen）214（SiW12O40） （phen = 1,10-phenanthroline）, has been synthesized by hydrothermal method and characterized with the aid of elemental analysis, IR, UV spectra and thermal analysis studies. The result of X-ray crystallography analysis exhibits that the title compound crystallizes in the orthorhombic space group P212121, and the formula is C96H64N16Cu4SiW12O40. Crystal data： a = 18.3574（14）, b = 21.1952（16）, c = 27.992（2）A, Mr = 4570.08, V = 10891.4（14）A^3, Z = 4, Dc = 2.787 g/cm^3,μ = 13.478 mm^-1, R = 0.0364, wR = 0.0638 （I 〉 2σ（I）） and F（000） = 8360. The complex consists of one α-Keggin anion [SIW12O40]^4- and four discrete [Cu^I（phen）2]^＋ cations. The valence sum calculations for the Cu atoms suggest that all four Cu atoms are in the ＋1 oxidation state.     

Synthesis,Structure and Properties of a Novel Copper（II）-2,2- biimidazole Complex-supported Compound： [Cu（H2biim）2] { [Cu（H2biim）2]2 [H10W12O44] }.8H2O

A new copper（II）-2,2＇-biimidazole metal-organic POMs-supported compound [Cu（H2biim）2]{[Cu（H2biim）212[H10W12O44]}＇8H2O （H2biim = 2,2＇-biimidazole） has been success- fully synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and TG. The crystal adopts space group Pi with a = 11.800（2）, b = 13.437（3）, c = 13.685（3） A, V = 1922.5（7） A3, D,. = 3.507 g/cm3, C36H62Cu3N24W12O52, M,. = 4059.92, F（000） = 1837,μ = 18.796 mm-1, Z = 1, R = 0.0579 and wR = 0.1465 for 8734 observed reflections （I 〉 2σ（I））. X-ray crystallography analysis exhibits that the title compound consists of one [H10W12044]6- polyanion and three [Cu（H2biim）2] units. And significant π-π stacking interactions and intermolecular O-H-,.O or N-H.＇-O hydrogen-bonding interactions lead to a three-dimensional supramolecular framework. Thermal stability and magnetic property of the complex have also been investigated.     

An Unprecedented 1D Zigzag Chain Alkaline Earth Metal Derivative {[Ba（DMF）3（H20）2][Ba（DMF）4]2（PzWl8O662）}n Containing Dawson Heteropolyanion

An unprecedented 1D zigzag chain alkaline earth metal derivative, {[Ba（DMF）3 （H20）2][Ba（DMF）412（P2W18O62）}n, （DMF=N, N-dimethyl formamide） containing Dawson hetero- polyanion has been successfully synthesized and characterized by X-ray crystallography. Two barium cations bridged by three DMF ligands in parallel combination with the Dawson-type heteropolyanion [P2W18O62]^6- and then the resulting subunits {[Ba（DMF）4]2（P2WlsO62）}^2＋ are alternately linked together via another [Ba（DMF）3（H2O）2]^2＋ ions, constructing a 1D zigzag chain architecture.     

Synthesis and Crystal Structure of a New Complex {[ Co^ⅢL2]·[Co^Ⅱ（H2O）6]0.6·2.25H2O }4 （H2L = N-（2-Hydroxyphenyl）salicylidenimine）

The reaction of Co（OAc）2·4H2O with the Schiff base H2L in a methanol solution affords the red crystals of { [Co^ⅢL2]·[Co^Ⅱ（H2O）6]0.5·2.25H2O}4 1 （H2L = N-（2-hydroxyphenyl） salicylidenimine）. The molecular and crystal structures were determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n, C104Hi14Co6NaO37, Mr = 2421.61, a = 10.625（3）, b = 16.335（4）, c = 15.265（4）A^°, β = 102.990（4）°, V= 2581.6（11）A^°^3, Z = 1, Dc= 1.558 g/cm^3,μ = 1.034 mm^-1, F（000） = 1252, R = 0.0414 and wR = 0.1167 for 5889 reflections. The Co（HI） atom is six-coordinated by two nitrogen atoms and four oxygen atoms of two tridentate L ligands. The abundant hydrogen bonding interactions extend the complex into a one-dimensional supra- molecular framework. The uncoordinated water molecules act as space-fillers and consolidate the whole architecture through the hydrogen bonding interactions.     

Syntheses and Crystal Structures of Two New Metal Phosphonates： [Mn（H2O）2（C12H8N2） （HO3PCH2CH2CO2） ] and [Co（H2O）4（C10H8N2）]-（HOaPCH2CH2CO2）

By the reactions of manganese（if） acetate, 2-sulfoethylphosphonic acid, 1,10-phen （1,10-phen = 1, 10-phenanthroline） or cobalt（Ⅱ） acetate, 4,4＇-bipy and 2-carboxyethylphosphonic acid, two novel compounds of [Mn（H2O）2（C12H8N2） （HO3PCH2CH2CO2） ] （1） and[Co（H2O）4（C10H8N2）]-（HOaPCH2CH2CO2） （2） have been synthesized and characterized by IR spectroscopy, elemental analyses and single-crystal X-ray diffraction. Compound 1 has a 0D structure. Two Mn（ii） ions are linked by two 2-carboxyethylphosphonic acid ligands, forming a centrosymmetric dimer. These dimers are further interlinked into a 2D layer structure by π-π stacking interactions and hydrogen bonds. Compound 2 has a 1D chain structure. The 2-carboxyethylphosphonic acid remains uncoordinated and acts as the organic template. By the bridge of 4,4＇-bipy, the [Co（4,4＇-bipy）]^2＋ chains are formed.     

Synthesis and Structural Characterization of Manganese Carbonyl Incorporated Polyoxomolybdate （n-Bu4N）2 [Mo6O16（OCH3）2 {HOCH2C（CH2O）3}2 {Mn（CO）3}2]

The polyoxoanion incorporated {Mn（CO）3^＋} complex, （n-Bu4N）2[Mo6O16（OCH3）2{HOCH2C（CH2O）3}2·{Mn（CO）3}2]（1）, has been synthesized by the reaction of （n-Bu4N）4[Mo8O26] with Mn（CO）5Br in methanol, in the presence of C（CH2OH）4. The complex 1 has been characterized by IR, UV-Vis, X-ray single crystal diffraction, and TG. Crystal data for the complex 1：C25H48MnMo3NO16 （1）, Triclinic Pi, a=0.9405（3） nm, b=1.3351（4） nm, c=1.5455（4） nm, α=103.206（5）°, β=102.165（5）°, γ=100.784（5）°, V=1.7896（9） nm^3, Z=2, R1=0.0703, wR2= 0.1495. The structure analysis of complex 1 shows that the complex consists of two tetrabutylammonium cations and a polyoxomolybdate anion that incorporates two fac-Mn（CO）3^＋ units. The anion of complex 1 can be considered as the dimer of two rhomb-like anions by sharing of two comers.     

A New Sandwich Type Transition Metal Substituted Polyoxotungstate under Hydrothermal Conditions： [NH3（CH2）4NH3]6[Co4（H2O）2（B-α-GeW9O34）2]}·7H2O

A new sandwich transition metal substituted polyoxotungstate, [NH3（CH2）4NH3]6[Co4（H2O）2（B-α-GeW9O34）2]}·7H2O 1, was hydrothermaUy synthesized and characterized by IR spectra and single-crystal X-ray diffraction. The single-crystal X-ray analysis reveals that the crystal crystallizes in monoclinic system, space group P21/c with a = 16.6073（6）, b = 15.3333（5）, c = 19.9869（7） A, β = 103.41（1）°, Mr = 5481.38, V = 4950.8（3） A3, Z = 2, Dc = 3.677 g/cm^3, F（000） = 4900, μ（MoKa） = 22.165 mm^-1, GOOF = 1.005, the final R = 0.0228 and wR = 0.0527. The crystal structure indicates that the [Co4（H2O）2（B-α-GeW9O34）2]^12- polyoxoanion contains two trivacant Keggin [B-α-GeW9O34]^10- fragments in a staggered fashion linked via a rhomb-like Co4O16 group in a centrosymmetric arrangement （C2h symmetry） leading to a sandwich-type structure.     

Synthesis, Characterization and Crystal Structure of an Inorganic-organic Composite Metatungstate: [Co(4,4'-bipy)2(H2O)4](4,4'-H2bipy)2[H2W12O40]·5.5H2O

A novel hybrid compound [Co(4,4'-bipy)2(H2O)4](4,4'- H2bipy)2[H2W12O40]·5.5H2Ohas been synthesized from an acidified aqueous solution and characterized by elemental and thermal analyses, IR and UV spectroscopy, and single-crystal X-ray structure determination. Structure analysis indicates that the title compound is of monoclinic, space group C2/c, with a = 21.315(9), b = 15.303 (7), c = 24.139(10) (A), β = 105.170(5)o, V = 7599(6) (A)3, Mr = 3706.99, Z = 4, F(000) = 6616, Dc = 3.231, μ = 18.395 mm-1, R = 0.0652 and wR = 0.1594. X-ray crystallographic study shows that the title compound consists of one [Co(4,4'-bipy)2(H2O)4]2 cation, two diprotonated 4,4'-bipyridine molecules, 5.5 water molecules of crystallization, and one metatungstate polyoxoanion [H2W12O40]6-, which approaches an effective Td point symmetry. TG-DTA analysis indicates that the framework of the metatungstate polyoxoanion is collapsed at 587.0 ℃.     

吡啶配位的夹心型杂多阴离子{[Na(H2O)2]3[Ni(C5H5N)]3(AsW9O33)2}9-的结构及磁学性质

The pyridine coordinated sandwich-type heteropolytungstate Na7[Ni（H2O）6] { [Na（H2O）2]3[Ni（C5H5N）]3（AsW9O33）2}·28H2O was obtained by the reaction of Na2WO4·2H2O, NaAsO2 and pyridine with NiCl2·6H2O at pH =7.0 and characterized by elemental analysis, IR, UV-Vis,^1H NMR spectra and magnetic measurement. The structure of this heteropolytungstate was determined by X-ray diffraction analysis, which crystallized in triclinic system, space group P1 with a= 1.3153（9） nm, b= 1.7228（12） nm, c=2.6866（19） nm, a=74.130（11）°,β=78.032（12）°, γ = 73.179（12）° and Z= 2, R1 = 0.0604, wR2 = 0.0915 [I〉 2σ（I）]. Polyanion {[Na（H2O）2]3[Ni（C5H5N）]3（AsW9O33）2}^9- has approximately C3 symmetry, and three pyridine coordinated Ni（C5H5N）^2＋ and three Na（H2O）2^＋ are encapsulated between two AsW9O33^9- . Magnetic measurements show that central Ni3 unit in the polyanion exhibits ferromagnetic Ni-Ni exchange interactions （J=6.17 cm^-1）.     

Synthesis and Structure of a POMs-based 3D Zeolike Ionic Crystal, {[Co（dpdo）2（H2O）2（CH3CN）]2（SiMo12O40）（H2O）2}n

A POMs-based 3D zeolike ionic crystal 1, {[Co（dpdo）2（CH3CN）（H2O）2]2（SiMo12O40）- （HEO）2}n （dpdo = 4,4＇-bipyridine-N,N＇-dioxide）, was constructed via self-assembly by embedding Keggintype [SiMo12O40]^4- polyanions within the intercrystalline voids as pillars and structurally characterized. The crystal structure was determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P1 with a = 11.430（3）, b = 12.242（3）, c = 14.279（3）A, α = 106.196（4）,β = 94.316（4）, γ = 98.294（3）°, V = 1884.5（7）A^3 Z = 1, C44H50N10O54CoEMo12Si, Mr = 2880.17, Dc = 2.538 g/cm^3, p = 2.484 mm^-1,F（000） = 1388, the final R = 0.0383 and wR = 0.1096 for 7753 observed reflections with I 〉 2σ（I）. Flack factor is 0.22（3）. Compound 1 is a pillar-layered framework with the [SiMo12O40]^4- anions linearly located on the square voids between the 2D bilayers which are formed by the dpdo ligands and cobalt（II） ions.     

Hybrid Tungstocuprate [Cu(2,2'-bpy)3]2H4[CuW12O40]·6H2O Based on Keggin Polyoxoanion [CuW12O40]6-with CuⅡas Heteroatom

A novel hybrid tungstocuprate(Ⅱ) [Cu(2,2'-bpy)3]2H4[CuW12O40]·6H2O(2,2'-bpy=2,2'-bipyridine) was synthesized via hydrothermal method and characterized using elemental analyses, IR, UV, XPS, TG-DSC, EPR, and X-ray single crystal diffraction. The structural analysis shows that the complex consists of an unusual Keggin-type polyoxoanion [CuW12O40]6- and a pair of chiral complex cations [Cu(2,2'-bpy)3] together with four protons and six crystallization water molecules, and the Keggin polyoxoanion is connected with [Cu(2,2'-bpy)3] via multiple C-H…O hydrogen bonds resulting in a dimer.