Compounds of the type RR’CNOM(C0)2CSHS (M = Mo and W; R’ = CH3, R = CH3, CH=CH2, CH=C(CH3)2, and
(CHJ2CH=CH2; R + R’ = (CH,),) can be prepared by the following three methods: (1) reaction of RR’C=NOSn(CH3)’ with CSH5M(CO),CL; (2) reaction of RR’C==NOLi with CSH5M(CO),C1; (3) reaction of RR’C=NOH with CSH5M(C0)3CI in the presence of pyridine. Ultraviolet irradiation is necessary for the syntheses of the tungsten compounds but not for their molybdenum analogues. The proton and carbon-1 3 NMR spectra of the ten RR’CNOM(C0)2C5H5 derivatives are described and discussed.