Thiolate Ligand Transfer from Metallothiolates to Phosphido-Bridged Heterobimetallic Compounds: C−S Bond Cleavage in Benzenethiol and Formation of a Mixed-Metal Trinuclear Compound

Thiolate ligand transfer occurred during the reaction between CpMo(CO)3SPh and (1) in dichloromethane at reflux, resulting in the new mixed-metal
and mixed-ligand bridged compound (2). However, when
CpW(CO)3SPh reacted with 1 under similar conditions, 2 and the mixed-metal trinuclear
compound (4) were formed. The presence
of the (μ-S)2 bridges in 4 indicates C−S bond cleavage in the SPh ligand. Reflux of a
dichloromethane solution of 1 and PhSH also produced 2 along with (3) and (5). Moreover, the
same reactants in benzene at reflux gave 2, 3, 5, and the additional product (6). The reaction of 1 with Ph2S2 in dichloromethane at reflux
produced compounds 2 and 3. Similarly conducted reactions in benzene at reflux afforded
2, 3, and 6. Compounds 2−6 were characterized by single-crystal X-ray diffraction analyses.
Formation of the PPh3 ligand, which coordinated to 6, suggests C−S bond cleavage in PhSH
and Ph2S2. Compounds 3, 5, and 6 were also synthesized in high yield by refluxing 2 with
PhSH or Ph2S2, PPh2H, and PPh3, respectively, in benzene.