Two 3D Cd(II) coordination polymers based on novel metallacalix[4]arenes molecular building blocks: Syntheses, structures and fluorescence properties

Abstract Two 3D Cd(II) coordination polymers, [Cd(H 2 BIDC)] n ( 1 ) and {[Cd 4 (H 2 BIDC) 4 (BIMB) 4 ]·5H 2 O} n ( 2 ), were synthesized under hydrothermal conditions [H 4 BIDC = 1H,1′H-[2,4′-biimidazole]-4,5-dicarboxylic acid, BIMB = 1,4-bis(1H-imidazol-1-yl)benzene]. Both two complexes consist of novel metallacalix[4]arenes MBBs Cd 4 (H 2 BIDC) 4 , which formed by H 2 BIDC 2− ligands linking Cd(II) ions in bis-chelating fashion or by the combination of bis-chelating and chelating-monodentate fashions. Complex 1 exhibits a lig network constructed from interconnecting C 2 -symmetric Cd 4 (H 2 BIDC) 4 MBBs and complex 2 displays a new 6-connected network built by ancillary BIMB ligands bridging S 4 -symmetric MBBs. Moreover, the purity, thermal stability and fluorescence property of two complexes were investigated.