Structures And Properties Of The Polyacid Compounds Of Dicarboxylic Acid/Dimethanol Bipyriddine Silver/Copper Complexes

We get ten new examples of polyacid compounds of silver/copper complexes based on four bispyridine organic ligands(2,2'-bipyridine-5,5'-dicarboxylic acid(H₂L₁),2,2'-bipyridine 4,4-dicarboxylic acid(H₂L₂),2,2'-bipyridine-5,5'-dimethanol(H₂L₃),and 2,2'-bipyridine-5,5'-dimethyl(H₂L₄)).They are synthesized based on hydrothermal reaction and solution reaction.Ten polyacid compounds were characterized by electrochemical AC impedance,thermogravimetric analysis,X-ray crystal diffraction,and isothermal water adsorption.The specific content is as follows:(1)Five polyacid compounds were obtained by hydrothermal syntheses of organic ligands(H₂L₁,H₂L₂ and H₂L₃),silver and Keggin polyacids in a high temperature environment:H[Ag(bpy)(NO3)]{[Ag(H₂L₁)₂]₂[Ag(H₂L₁)][Si W₁₂O₄₀]}(1),H[Ag(H₂L₁)₂]₂[PW₁₂O₄₀]·bpy·4.5H₂O(2),[Ag(H₂L₂)₂]₂{[Ag(H₂L₂)₂]₂[Si W₁₂O₄₀]}·4H₂O(3),[Ag(H₂L₃)₂]₂[Ag(H₂L₃)₂][Ag(H₂L₃)][Si W₁₂O₄₀](4),and H₃[Ag(HL₃)]₂[Ag₂(L₃)][PW₁₂O₄₀]·2H₂O(5).The datas show that 1 and 2 are Keggin type polyacid compounds based on the complexes of Ag(I)ions and H₂L₁ ligand.The metal organic complex ions[Ag(H₂L₁)₂]⁺and[Ag(H₂L₁)]⁺in 1 are linked to the polyacid negative ion to form a tetra-supported polyacid cluster based on coordination bonds;the polyacid negative ion in 2 acts as a counter ion in the polyacid compound and do not form coordination bonds with metal organic cations,which form a two-dimensional cation layer through self-assembly.3 is a polyacid compound based on Ag(I)ions and H₂L₂ ligand.Each of Keggin-type negative ions links with two[Ag(H₂L₂)₂]⁺metal organic cations through coordination bonds.4 and 5 are polyacid compounds based on Ag(I)ions and H₂L₃ligand.The Ag(3)-organic complex ions in 4 are connected to the Keggin-type negative ions via coordination bonds of bridging oxygen atoms to form a one-dimensional chain.The metal-organic complex ions based on Ag(1)and Ag(2)centers are distributed between the one-dimensional chains to give a two-dimensional layer.The metal-organic cations[Ag₂(L₃)]in 5 link with the Keggin-type negative ions via coordination bonds of terminal oxygen atoms to form a one-dimensional chain.The crystal skeleton structure of each of five polyacid compounds can remain intact before 300°C;more than twenty moles of water molecules are adsorbed per mole of each of five compounds at normal temperature and pressure;the proton conductivity of each of five compounds increases with temperature and increases in varying degrees.(2)Organic ligands H₂L₁,copper ions and Keggin-type polyacid?-H₃PMo₁₂O₄₀·6H₂O gave two polyacid compounds in a high-temperature environment:[Cu₇Cl₃(HL₁)₃(L₁)₃(H₂O)₆]H[PMo₁₂O₄₀]·7H₂O and{[Cu(HL₁)(H₂O)₂][Cu(H₂L₁)(H₂O)₂][PMo₁₂O₄₀]}·5H₂O(7).The datas show that the copper ions in 1 adopt a six-coordination mode,and the bimetallic organic clusters containing copper ions are connected together to form a single-stranded and right-handed spiral.The Keggin-type negative ions in 7 are connected to form a one-dimensional double chain through coordination bonds with metal organic coordination ions.The molecular weight of adsorbed water per mole of each of two compoounds at normal temperature and pressure is about twenty moles;the Ea value of each of two compounds is similar to the conductivity activation energy of the Keggin-type polyacid.(3)Three polyacid compounds were obtained by solution syntheses of organic ligands(H₂L₃ and L₄),copper ions and Keggin-type polyacid in room-temperature environment:[Cu(H₂L₃)(H₂O)₂]₂[Si W₁₂O₄₀]·7H₂O(8),H₂[Cu₂(IN)₂(H₂L₃)(H₂O)₂][Si W₁₂O₄₀]·2CH₃CN·2H₂O(9),and H₂[Cu₂(IN)₂(L₄)(H₂O)₂][Si W₁₂O₄₀]·2CH₃CN·3.5H₂O(10).The data shows that 8 is a polyacid compound based on Cu(II)ions and H₂L₃ ligand.Each of the metal-organic clusters in 8 is covalently bonded to two adjacent Keggin type negative ions through a copper atom,and each Keggin type anion is connected to four metal organic cations through four terminal oxygen to form a two-dimensional layer.9 is a polyacid compound based on Cu(II)ions,H₂L₃ and HIN ligands with the double-metal cluster[Cu₂(IN)₂(H₂L₃)(H₂O)₂]²⁺.10 is a polyacid compound based on Cu(II)ions,L₄ and HIN ligands with the double-metal cluster[Cu₂(IN)₂(L₄)(H₂O)₂]²⁺.The molecular weight of adsorbed water per mole of each of three compounds at room temperature and pressure are not much different;all three compounds have good electrical conductivity,and their proton conductivity is maintained at 10^-6S·cm^-1?10^-5S·cm^-1.