Coordination polymers of zinc and cadmium thiocarboxylates with 4,4′-bipyridine ligands

The reaction of M(SC{O}R)(2) with 4,4'-bipyridine (bpy) in the ratio 1:1 gives [{M(SC{O}R)(2)(mu-bpy)}(n)] [R = Me, M = Zn (1) and Cd (2); R = Ph, M = Zn (3) and Cd (4)]. The compound [{Cd-2(SC{O}Ph)(4)(p-bpy)}(n)] (5) was obtained from Cd(SC{O}Ph)(2) and bpy in the ratio 2:1. The structures of 1, 3, 4 and 5 have been determined by X-ray crystallography. All these compounds have one-dimensional zigzag polymeric structures. In 5, the repeating unit has two Cd(II) bridged by S atoms of the two Ph{O}CS- ligands and each carbonyl oxygen atom of the bridging ligands is bonded to a Cd(II) atom so that the two PhC{O}S- anions have S-2, O bonding mode. Each Cd(II) is further attached to a chelating thiobenzoato ligand and bridged by a bpy ligand. The bridging nature of the thiobenzoate anion observed in 5 is hitherto unknown for Group 12 metal compounds. All the compounds decompose to the corresponding metal sulfides in nitrogen atmosphere, according to weight loss observed in TG. Compounds 1-3 provided cubic phases of the metal sulfides while 4 and 5 gave hexagonal CdS from pyrolysis as confirmed by XRD. (C) 2002 Elsevier Science B.V. All rights reserved.