Synthesis, structures and electrocatalytic properties of coordination polymers of 4,4′,4′′,4′′′-tetrakiscarboxyphenylsilane and 1,3,5-tris(2-methyl-1-imidazol-1-yl)benzene

Four Ni, Co, Cu, Zn-containing coordination polymers incorporating 4,4′,4′′,4′′′-tetrakiscarboxyphenylsilane (H 4 tcps) and 1,3,5-tris(2-methyl-1 H -imidazol-1-yl)benzene (tmib) ligands, namely [Ni 6 (tcps) 3 (tmib) 4 (H 2 O) 2 ] ( 1 ), [Co 6 (tcps) 3 (tmib) 4 ] ( 2 ), [Cu 2 (tcps)(tmib)(H 2 O)] ( 3 ) and [Zn 2 (tcps)(tmib)] ( 4 ), were synthesized by the solvothermal method. Compounds 1 and 2 were isostructural with three-dimensional (3D) (3,4)-connected frameworks. Compounds 3 and 4 possessed (3,4)-connected 3D networks with (6·8 2 )(6·8 5 )(6 2 ·8 2 ·10 2 )(6 2 ·8) and (4·6·8)(4·6 3 ·8 2 )(6 6 )(6 7 ·8 3 ) topology, respectively. The thermal derivatives of compounds 1 and 2 , Co-800 and Ni-700, exhibited low OER overpotentials of 338 and 388 mV to achieve a current density of 10 mA cm −2 and hold their electrocatalytic activity for at least 9 hours in 1 M KOH. Coordination polymers based on H 4 tcps and tmib were synthesized, and the pristine crystals and thermal derivation composites were converted into their metal hydroxides and oxidized hydroxides in alkaline solution as OER catalysts.