Structures And Properties Of The Complexes Of Polyacids And Diethoxycarbonyl/Dimethanol Bipyriddine Copper Complexes

The syntheses of novel organic-inorganic complexes have promoted the development ofcomposites materials,in which the functions of organic components and inorganic components have been well preserved.In addition,the overall performance of the hybrid material is better than those of the individual components because of the synergistic effect.The Keggin-type heteropolyacids with spherical structures show good proton conductivities.The novel organic-inorganic composites formed by coordination bonds,hydrogen bonds and electrostatic interactions between Keggin-type heteropolyacids and organic components are greatly improved in terms of proton conductivity and stability.We synthesized 8 new organic-inorganic compounds,which are based on Keggin-typeheteropolyacidandcoppercomplexesof4,4'-bis?ethoxycarboxyl?-2,2'-bipyridine?debpdc?/4,4'-bis?hydroxymethyl?-2,2'-bipyridine?dbhybp?.8 complexes have been structurally characterized by Fourier infrared spectroscopy and elemental analyses,X-ray single crystal and powder diffraction analyses.Furthermore,their thermal stabilities,isothermal water adsorption properties,electrochemical impedance behaviors and proton conductivities have also been investigated.The specifics as follows:?1?Three novel proton-conductive composites based on single and double decorated Keggin clusters,{[Cu?debpdc??H₂O?₃][Cu?debpdc??H₂O?Cl][PMo₁₂O₄₀]}·2CH₃OH·2CH₃CN·4H₂O?1?,{[Cu?ebpdc??H₂O?₃][Cu?debpdc??H₂O?Cl][PW₁₂O₄₀]}·2CH₃OH·6H₂O?2?and[Cu?debpdc??H₂O?₃][H₂SiW₁₂O₄₀]·14H₂O?3?,weresynthesizedbythereactionsof?-H₃PMo₁₂O₄₀·24H₂O(or?-H3PW₁₂O₄₀·6H₂O,?-H₄SiW₁₂O₄₀·24H₂O),CuCl₂·2H₂O and debpdc at room temperature.The results of single crystal X-ray diffraction analyses revealed that both debpdc and ebpdc ligands act as bidentate nitrogen donor ligands in the chelating fashion.the ebpdc ligand should come from the debpdc ligand based on the hydrolyzation of one ester group in situ.Keggin-type anions of 1 and 2 as bidentate inorganic components coordinate with metallic organic components to form double decorated Keggin clusters.However,the Keggin-type anion of 3 as a monodentate inorganic component coordinates with metallic organic components to form a single decorated Keggin cluster.These Keggin clusters rely on the hydrogen bonds interaction to form three-dimensional supramolecular complexes with one-dimensional hydrophilic channels or two-dimensional hydrophilic layers.Three novel proton-conductive composites show well proton conductivities of 10^-610^-5S·cm^-1?1?,10^-510^-4S·cm^-1?2?,10^-5S·cm^-1?3?from 25 to 100°C under a RH of 98%.?2?Furthermore,we synthesized three proton-conductive novel organic-inorganic composites based on quadri-decoratedsupportedKegginclusters,{[Cu?dbhybp??H₂O?₂]₂[PMO₁₂O₄₀]}{[Cu?dbhybp??H₂O?Cl]₂[PMO₁₂O₄₀]}·4CH₃OH·14H₂O?4?,{[Cu?dbhybp??H₂O?₂]₂[PW₁₂O₄₀]}{[Cu?dbhybp??H₂O?Cl]₂[PW₁₂O₄₀]}·4CH₃OH·14H₂O?5?and{[Cu?dbhybp??H₂O?₂]₂[SiW₁₂O₄₀]}₂·14H₂O?6?,bythereactionsofa-H₃PMo₁₂O₄₀·24H₂O(or a-H₃PW₁₂O₄₀·6H₂O??-H₄SiW₁₂O₄₀·24H₂O),CuCl₂·2H₂O and dbhybp.On this basis,we synthesized two novel organic-inorganic complexes,{H₂[Cu?dbhybp??in??CH₃CN?][PMo₁₂O₄₀]·hin·CH₃CN·4H₂O}₂?7?and{H₂[Cu?dbhybp??in??H₂O?]₂[Si W₁₂O₄₀]}·6H₂O?8?,by adding isonicotinic acid?hin?.The results of single crystal X-ray diffraction analyses indicated that they crystallized in the monoclinic space groups P2₁/c for4-6.In three complexes,dbhybp was coordinated as a bidentate nitrogen donor with Cu²⁺.The Keggin-type anion acts as tetradentate inorganic component to coordinate with four metal organic components to form two supported structures.The two supported structures form two kinds of two-dimensional layers through hydrogen bonds or coordination bonds.Two kinds of two-dimensional layers are stacked into a three-dimensional supramolecular structure through the ABAB packing.The results of single crystal X-ray diffraction analyses showed that 7 and 8 were crystallized in the triclinic space groups P^—1.Dbhybp as a tridentate organic components and hin as a monodentate organic components coordinated with coppers to form a bimetallic organic cluster.The bimetallic organic clusters and Keggin heteropolyacids form novel organic-inorganic complexes by hydrogen bonds?7?or coordination bonds?8?.Proton conductivity analysis showed that these five complexes have good proton conductivities of 10^-510^-4S·cm^-1?4?6?8??10^-4S·cm^-1?5??10^-3S·cm^-1?7?at a relative humidity of 98% in the temperature range of 25? to 100?.