M–Ru–Sn (M = Re, Mn) heterometallic and Ru–Sn bimetallic carbonyl complexes bearing heterocyclic thiolato ligands

Abstract

The present study reports the synthesis and characterization of some heterogenic tri- and bimetallic carbonyl complexes of Re, Ru, Mn, and Sn containing heterocyclic thiolato ligands. Three new heterometallic complexes [ReRu(CO)5(Ph3Sn)(μ-pyS)(μ-MBT)] (5), [ReRu(CO)5(Ph3Sn)(μ-pyS)2] (6) and [MnRu(CO)5(Ph3Sn)(μ-pyS)2] (7) bearing bridging heterocyclic thiolato ligands (pyS = pyridine-2-thiolato; MBT = 2-mercaptobenzothiolato) were obtained from the reactions of [Ru2(CO)4(Ph3Sn)2(μ-pyS)2] (1) with each of [Re2(CO)6(μ-MBT)2] (2), [Re2(CO)6(μ-pyS)2] (3) and [Mn2(CO)6(μ-pyS)2] (4) respectively in CH2Cl2 at room temperature. The identity of 7 was further substantiated by its reaction with PPh3, which produced the previously reported mononuclear complexes [Ru(CO)2(Ph3Sn)(PPh3)(pyS)] and [Mn(CO)3(PPh3)(pyS)]. Compound 1 reacts with bidentate nitrogen donor ligands, 1,10-phenanthroline (phen) or 2,2′-bipyridine (bipy) at room temperature, to produce the κ1(S)-coordinated pyridine-2-thiolato and κ2(N)- chelating phen or bipy complexes [Ru(CO)2(SnPh3)(κ2-phen)-{κ1-(S)-pyS}] (8) and [Ru(CO)2(SnPh3)(κ2-bipy){κ1-(S)-pyS}] (9), respectively. Heterobifunctional monophosphines, such as tri(2-furyl)phosphine (PFu3) and tris(2-thienyl)phosphine (PTh3), and diphosphines such as dppm [bis(diphenylphosphino)methane] react with 1 to give homologous compounds [Ru(CO)2(SnPh3)(PFu3)(κ2-pyS)] (10), [Ru(CO)2(SnPh3)(PTh3)(κ2-pyS)] (11) and [Ru(CO)2(SnPh3)(κ1-dppm)(κ2-pyS)] (12), respectively, in which the pyS ligands chelate through the S and N atoms. All the new compounds, 5–12, were characterized based on their elemental analyses, IR, and NMR spectroscopy. In addition, the molecular structures of four representative compounds (5, 8, 10, and 12) were unambiguously established by single-crystal X-ray diffraction analysis. The bonding in these complexes, together with starting dimers 1 and 2, has been investigated by electronic structure calculations.