Metal Derivatives of Thiosemicarbazones: Crystal and Molecular Structures of Mono‐ and Dinuclear Copper(II) Complexes with N 1 ‐Subsitituted Salicylaldehyde Thiosemicarbazones

Reactions of copper(II) acetate with N 1 ‐subsitituted salicylaldehyde thiosemicarbazones [ R 1 R 2 C 2 =N 3 –N 2 H–C 1 (=S)–N 1 H R 3 ; R 1 = 2‐HO–C 6 H 4 –, R 2 = H : R 3 = Me (H 2 L 1 ), Et (H 2 L 2 )] are described. Copper(II) acetate was reacted with H 2 L 1 and H 2 L 2 ligands in the presence of polypyridyl co‐ligands, and this led to the formation ofmononuclear complexes, [Cu(κ 3 ‐O, N, S‐L 1 )(κ 2 ‐N, N‐bipy)] ( 1 ),[Cu(κ 3 ‐O, N, S‐L)(κ 2 ‐N, N‐phen)] [L = L 1 ( 3 ), L 2 ( 4 )], [Cu(κ 3 ‐O, N, S‐L)(κ 2 ‐N, N‐tmphen)] [L =L 1 ( 5 ), L 2 ( 6 )] and a dinuclear complex, [Cu 2 L 2 2 (bipy)] ( 2 ) (bipy = 2, 2′‐bipyridine, phen = 1, 10‐phenanthroline, tmphen = 3, 4, 7, 8‐tetramethyl‐1, 10‐phenanthroline). In dinuclear complex 2 , one ligand is O, N 3 ,S‐chelating, while second is O, N 3 ,S‐chelation‐cum‐N 2 ‐bridging; and in all others thio‐ligands are O, N 3 ,S‐chelating. The μ eff values for the complexes lie in the range of 1.79–1.83 BM. Complexes 1 , 3 – 6 have square pyramidal arrangement, whereas complex 2 has two independent molecules in the crystal lattice, and each molecule has trigonal bipyramidal square planar (5:4) coordination pair. Complexes 2 , 4 , and 6 showed fluorescence properties.