A new 2d coordination polymer based on zinc(ii), 1,2,3-benzenetricarboxylic acid and 4,4ʹ-bis(imidazol-1-ylmethyl)biphenyl: synthesis and crystal structure

The solvothermal reaction of zinc(II) nitrate with 1,2,3-benzenetricarboxylic acid (1,2,3-H3BTC) and 4,4ʹ-bis(imidazol-1-ylmethyl)biphenyl (BIBPh) produced a crystalline solid {[Zn3(BIBPh)3(BTC)2]∙H2O}n. The product has been structurally characterised and investigated by X-ray diffraction, IR and thermogravimetric methods. The polymer has a bidimentional structure and crystallizes in the P21/c space group of the monoclinic system with the following unit cell parameters: a= 14.8687(16), b= 36.915(4), c= 13.8378(16) (Å), β= 105.584(6)°. The asymmetric unit of the crystal structure contains three zinc(II) ions, three BIBPh ligands and two BTC3- monodentate ligands with all three deprotonated carboxylate groups that balance the overall charge. All zinc centers have similar coordination environment: each metal ion is four coordinated exhibiting a slightly distorted tetrahedral coordination, where two positions are occupied by oxygen atoms of the carboxylic acid and the other two by nitrogen atoms of imidazole subunits