ISSN 1070-3284, Russian Journal of Coordination Chemistry, 2007, Vol. 33, No. 12, pp. 886–890. © Pleiades Publishing, Ltd., 2007. 886 1 INTRODUCTION Photosubstitution of group VI metal carbonyls is a highly efficient process which provides convenient access to a large variety of mono- and polysubstituted derivatives [1]. Carbonyl compounds with sulfur and nitrogen donor ligands continue to attract considerable attention not only on account of their fascinating struc- tural chemistry but also because of their ability to act as electron reservoirs and their potential in catalysis [2]. Features of the chemistry of these molecules which are currently of interest include the mechanisms and sites of substitution as well, as the modification of reactivity accompanying carbonyl replacement by donor ligands [3]. Photosubstitutions of CO with the formation of M(CO) 5 L (M = Cr, Mo, W) from VIB group metal car- bonyls M(CO) 6 were studied with a variety of σ-donor ligands L (L are Schiff base derivatives) [4]. In order to contribute to these studies, we tried to substitute these ligands to the metal center as bi- or polydentate che- lates. Along with our continued interest in the photo- chemical synthesis and structural aspects of VIB group metal carbonyls led us to launch an exploratory investi- gation into the photolytic behavior of the cis-[(η 4 - NBD)M(CO) 4 ] (NBD is norbornadiene) complexes in the presence of ligands containing sulfur and nitrogen donor atoms [5]. 1 The article was submitted by the authors in English. Initially, here we describe a particularly convenient photochemical route to the synthesis of cis-[(η 4 - NBD)M(CO) 4 ] (M = Cr, Mo). Then we investigated the behavior of cis-[(η 4 -NBD)M(CO) 4 ] (M = Cr, Mo) with the title ligands 5-(4-dimethylaminobenzylidene)rhoda- nine (DABRd) and salicylidene–3-amino–1,2,4-tria- zole (SAT) which contain the pentagonal heterocycle rhodanine and 1,2,4-triazole ring, respectively. New complexes cis-[M(CO) 4 -DABRd] (M = Cr (I), Mo (II)) and fac-[M(CO) 3 -SAT] (M = Cr (III), Mo (IV)) have been synthesized by the photochemical reactions of [(η 4 -NBD)M(CO) 4 ] (M = Cr, Mo) with DABRd and SAT ligands and characterized by elemental analysis, FT-IR and 1 H NMR spectroscopy, and mass spectrome- try. The spectroscopic studies show that DABRd ligand acts as a bidentate ligand coordinating via both sulfur NH–(S)C = S donor atoms in I and II, and SAT ligand behaves as a tridentate ligand coordinating via its all imine nitrogen –C = N– donor atoms in III and IV to the metal center. EXPERIMENTAL Materials and methods. All reactions and manipu- lations were carried out under argon and in argon-satu- rated solvents using Schlenk techniques. All solvents were dried and degassed using standard techniques [6]. All organic solvents and silica gel were purchased from Merck and M(CO) 6 (M = Cr, Mo, W) were from Ald- rich. DABRd [7] and SAT [8] were prepared by litera- Photochemical Reactions of cis-[(h 4 -NBD)M(CO) 4 ] (NBD = Norbornadiene; M = Cr, Mo) Olefin Complex with Ligand, Containing S and N Donor Atoms 1 E. Subasi a , S. Karahan a , and A. Ercag b a Department of Chemistry, Faculty of Science and Literature, Dokuz Eylul University, 35160 Izmir, Turkey b Department of Chemistry, Faculty of Engineering, Istanbul University, 34850 Istanbul, Turkey e-mail: elif,subasic@deu.edu.tr Received August 17, 2006 Abstract—New complexes cis-[M(CO) 4 -DABRd] (M = Cr(I), Mo(II) and fac-[M(CO) 3 -SAT] (M = Cr(III), Mo(IV)) have been synthesized by the photochemical reactions of cis-[(η 4 -NBD)M(CO) 4 ] (NBD is norborna- diene; M = Cr, Mo) with 5-(4-dimethylaminobenzylidene) rhodanine (DABRd) and salicylidene-3-amino- 1,2,4-triazole (SAT) ligands and characterized by elemental analysis, FT-IR and 1 H NMR spectroscopy, and mass spectrometry. The spectroscopic studies show that the DABRd ligand acts as a bidentate ligand coordi- nating via both NH–(S)C=S sulfur donor atoms in I and II and SAT ligand behaves as a tridentate ligand coor- dinating via its all imine nitrogen –C=N– donor atoms in III and IV to the metal center. DOI: 10.1134/S1070328407120032