1594 [Cr2Hg(CO)6(C8H902)2] References B. A. Frenz & Associates, Inc. (1982). SDP Structure Determina- tion Package. College Station, Texas, USA. Curtis, M. D. & Butler, W. M. (1978). J. Organomet. Chem. 155, 131-145. Klinger, R. J., Butler, W. M. & Curtis, M. D. (1978). J. Am. Chem. Soc. 100, 5034-5038. Main, P., Fiske, S. J., Hull, S. E., Lessinger, L., Germain, G., Declercq, J.-P. & Woolfson, M. M. (1982). MULTAN11/82. A System of Computer Programs for the Auwmatic Solution of Crystal Structures from X-ray Diffraction Data. Univs. of York, England, and Louvain, Belgium. Song, L.-C., Dong, Q. & Hu, Q.-M. (1992). Acta Chim. Sin. 50, 193-199. Song, L.-C., Wang, J.-Q., Hu, Q.-M., Wang, R.-J. & Wang, H.-G. (1993). Polyhedron, 12, 259--261. Song, L.-C., Yang, H., Dong, Q. & Hu, Q.-M. (1991). J. Organo- met. Chem. 414, 137-143. atom potentially available for coordination to one or more metal centres in a variety of ways (Raper, 1985). Although extensively studied by spectroscopic meth- ods, crystallographic investigations of zinc and cad- mium complexes of this ligand have been limited (McCleverty et al., 1982; Hursthouse, Khan, Mazid, Motevalli & O'Brien, 1990). We have recently reported the synthesis of the complexes [M(C7H4NS2)2(py)2], [M(C7H4NS2)2(2,2'-bpy)] and [M(C7HaNS2)2(phen)] (py = pyridine, phen = phenanthroline, bpy = bipyri- dine, M = Zn or Cd) and the single-crystal structures of [Zn(C7H4NS2)2(py)2], [Zn(CTH4NS2)2(2,2t-bpy)] and [Cd(C7H4NS2)2(py)2] (Baggio, Garland & Perec, 1993). The three adducts were found to be monomeric, with distorted tetrahedral ZnN2S2 and distorted octahedral CdN4S2 cores, respectively. Acta Cryst. (1994). C50, 1594-1596 Bis(1,3-benzothiazole-2-thiolato-N,S')- (2,2"-bipyridine-N,N')cadmium(II) Rac~ F. BAGGIO Divisi6n Fisica del S61ido, Departamento de Fisica, Comisi6n Nacional de Energfa At6mica, Buenos Aires, Argentina MIRI~.rl J.E PEREC Departamento de Quimica Inorg6nica, Anafftica y Quimica Fisica, Facultad de Ciencias Exactas y Naturales, UNBA, Buenos Aires, Argentina MARXA TERESA GARLAr~ Departamento de Fisica, Facultad de Ciencias Fisicas y Matem6ticas, Universidad de Chile, Santiago de Chile, Chile (Received 20 January 1994; accepted 10 April 1994) Abstract The title tds-chelate complex [Cd(CTH4NS2)2 - (CloHsN2)] is monomeric, with a coordination sphere of the type N4S2. The Cd atom is linked to two thiazole N atoms and two exocyclic S atoms from two bidentate 1,3-benzothiazole-2-thiolate anions and two bipyridine N atoms. The Cd-atom coordination geometry is trigo- nal prismatic. Comment The 1,3-benzothiazole-2-thiolate (mbt-) anion, C7H4- NS~-, is a versatile ligand with more than one donor \/ 1-" Cd-......~ (1) This report presents results of the crystal structure de- termination of the tris-chelate complex [Cd(C7H4NS2)2- (2,2'-bpy)], (1). Fig. 1 presents the structural diagram and the atomic numbering scheme. The Cd atom lies on the twofold axis and its environment can be adequately described as trigonal prismatic, with no appreciable rota- tion (< 1°) from the regular geometry of the two basal planes defined by N1, N2 !, S1 and NI', N2, SI', respec- tively (primes denote atoms generated by the twofold rotation). The intrachelate angles S---Cd--N and N-- Cd--N are in the narrow range 62.5 (1)-69.2 (3) ° and reflect the rigid chelate geometry in (1). In the complex [Cd(CvI-I4NS2)2(py)z] already noted, the average intra- chelate angle S----Cd--N is 62.1 (1) ° and the N(py)--- Cd--N(py) angle is 94.9(2) °. Thus, substitution of the two pyridine N atoms by the bpy N atoms of the bidentate ligand leads to a configuration of three almost equivalent 'bites', with a mean normalized value of 1.05 (Kepert, 1977). Kepert's rules predict for this case a rather undistorted trigonal prismatic geometry as the most stable configuration, in accordance with the present results. Comparison of complex (1) with [Zn(C7H4NSz)2(2,2t-bpy)] noted above reveals that in the latter, the mbt- ligands are bonded through the exocyclic S atom only, resulting in a distorted tetrahe- dral ZnN2S2 geometry. The larger size of the Cd atom allows S,N-bidentate bonding of the two mbt- ligands. These structures illustrate the differences in coordina- tion that can result in zinc(H) and cadrniurn(ID thiolates and may be relevant to their different biological activity (Reddy, Zhang, Schlemper & Schrauzer, 1992). © 1994 International Union of Crystallography Printed in Great Britain - all fights reserved Acta CrystallographicaSection C ISSN 0108-2701 ©1994