New CuII and CdII Metal-organic Coordination Polymers with 1,2,4-triazolo[3,4- b]-1,3,4-thiadiazole Ligands: Syntheses, Structures and Luminescent Properties.

Three new complexes {[Cu( L1)2(NO3)2]⋅H2O}oo ( 1), {[Cu4( L2)2(OAc)8]-CH3CH2OH}oo ( 2) and [Cd2( L3)3(NO3)4(H2O)2]oo ( 3) ( L1=4-phenyl-7-(pyridine-3-yl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole, L2=4-(pyridine-3-yl)-7-phenyl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole, and L3=4-(pyridine-4-yl)-7-phenyl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole) have been synthesized and characterized by elemental analyses, IR spectra and single crystal X-ray diffraction. The structural analyses reveal that complex 1 is a neutral 2-D network structure with a 44 topology, 2 has a 1-D neutral coordination chain with a [Cu2(CH3COO)4] dinuclear structural unit bridged by four acetate ions, and 3 is a neutral rhombohedral grid structure. All the complexes are air stable at room temperature. Furthermore, the fluorescent properties of complex 3 and corresponding ligand L3 have been investigated and discussed. [ABSTRACT FROM AUTHOR]