Anion-controlled assembly of metal 3,5-bis(benzimidazol-1-ylmethyl) benzoate complexes: Synthesis, characterization and property

•Metal complexes have diverse structures of 1D chains, 2D networks and 3D frameworks.•Anion-controlled assembly of the complexes is reported.•The luminescent properties of the Cd(II) and Zn(II) complexes were investigated.

Hydrothermal reactions of 3,5-bis(benzimidazol-1-ylmethyl)benzoic acid (HL) with Cd(II), Cu(II) and Zn(II) salts provide eight new metal complexes which were characterized by single crystal and powder X-ray diffraction, IR, elemental and thermogravimetric analyses. Two cadmium frameworks [Cd(L)2]·2H2O (1) and [Cd(L)Cl] (2) have 3D structures with (42.65.83)(42.6) and rtl (4.62)2(42.610.83) topologies, respectively. Structural diversity of four copper complexes [Cu3(L)2]·NO3·0.5H2O (3), [Cu2(HL)2(SO4)]·3.5H2O (4), [Cu(L)(bdc)0.5]·1.5H2O (5) and [Cu2(L)(HL)(Hbdc)] (6) (H2bdc=1,4-benzenedicarboxylic acid) is achieved through the alteration of copper salts and addition of auxiliary ligand. As a result, 3 has a 1D ladder structure, 4 is a discrete dinuclear complex, 5 displays a (3,4)-connected 2-nodal 3-fold interpenetrating framework with (42.6.102.12)(42.6) topology, 6 exhibits a 4-connected uninodal 2D sql (44.62) network. Within the zinc series, ZnCl2 and ZnSO4 were used for the syntheses of [Zn(L)Cl] (7) and [Zn(L)(SO4)0.5]·2H2O (8), respectively. 7 shows a 3-connected uninodal 2D hcb network with (63) topology and 8 is a (3,6)-connected 2-nodal 3D framework with (42.6)2(44.62.88.10) topology. The luminescent properties of the Cd(II) and Zn(II) complexes were investigated.

Graphical abstractEight new complexes have been successfully synthesized from the hydrothermal reactions of Cd(II), Cu(II) and Zn(II) salts with 3,5-bis(benzimidazol-1-ylmethyl)benzoic acid. The complexes exhibited anion-controlled structural diversity.Figure optionsDownload full-size imageDownload as PowerPoint slide