New Cu II and Cd II 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( L 1 ) 2 (NO 3 ) 2 ]⋅H 2 O} oo ( 1 ), {[Cu 4 ( L 2 ) 2 (OAc) 8 ]‐CH 3 CH 2 OH} oo ( 2 ) and [Cd 2 ( L 3 ) 3 (NO 3 ) 4 (H 2 O) 2 ] oo ( 3 ) ( L 1 = 4‐phenyl‐7‐(pyridine‐3‐yl)‐1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazole, L 2 = 4‐(pyridine‐3‐yl)‐7‐phenyl‐1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazole, and L 3 = 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 4 4 topology, 2 has a 1‐D neutral coordination chain with a [Cu 2 (CH 3 COO) 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 L 3 have been investigated and discussed.