Assembly and properties of coordination polymers modulated by substituted 1,3-benzenedicarboxylates

Abstract

Four new coordination polymers [Co(bbbm)(1,3-BDC)]·H₂O (1), [Co₃(bbbm)₄(SIP)₂(H₂O)₂]·2H₂O (2), [Cd₃(bbbm)₃(SIP)₂(H₂O)₄]·2H₂O (3) and [Cd(bbbm)(NIP)] (4) (bbbm = 1,1-(1,4-butanediyl)bis-1H-benzimidazole, 1,3-H₂BDC = 1,3-benzenedicarboxylic acid, H₃SIP = 5-sulfoisophthalic acid and H₂NIP = 5-nitroisophthalic acid) have been hydrothermally synthesized and structurally characterized. Complex 1 possesses a two-dimensional (2D) (4,4) network structure. Co^II ions are connected by the 1,3-BDC anions to form one-dimensional (1D) linear chains, which are extended into 2D layers by the bbbm ligands. 2 shows a three-dimensional (3D) (3,4,5)-connected framework with a (6.8²)₂(6⁹.8)₂(8⁶) topology. In complex 2, Co-SIP ladder-like chains are linked by the bbbm ligands to generate a 3D framework. 3 exhibits a 3D (3,3,4,4,4)-connected framework with a novel (3.6.7³.8)(3.6.7)(3.6².7³)(6.7²)(6.7⁴.10) topology. Cd^II ions are connected by SIP anions to form 2D layers containing 12-membered macrocycle, which are further connected by the bbbm linkers to form a 3D framework. 4 displays a 3D 8-connected framework with a (4²⁴.6⁴) topology. In complex 4, binuclear cadmium clusters are extended into 3D structure by the bbbm ligands and NIP anions. The substituent group of polycarboxylates plays an important role in the assembly and structures of title complexes. The electrochemical properties of 1 and 2, photoluminescent properties of 3 and 4 have been reported.