EVIDENCE FOR THE ACTIVATION OF THIETANES TO RING-OPENING BY NUCLEOPHILES THROUGH BRIDGING COORDINATION

The reaction of Os3(CO)10(mu-SCH2CME2CH2) (1) with [Et4N]+Cl- in CH2Cl2 yielded after acidification the complex Os3(CO)10[mu-SCH2CMe2CH2Cl](mu-H) (3; 55%), which contains a chloroneopentanethiolato ligand that is believed to have been formed by the nucleophilic ring opening of the thietane ligand in 1. In contrast, the reaction of the ring-opened complex Os3(CO)10[mu-SCH2CMe2CH2] (4) with [Et4N]+Cl- yielded only the cluster-opened product [Et4N]+[Os3(CO)9(mu-SCH2CMe2CH2)-(mu-Cl)]- (5; 87%). Compounds 3 and 5 were characterized crystallographically.