Insertion of CS2 into a metal acetylide bond and conversion of the bonding mode of S2CC≡CPh from η2 to η3

Abstract

Photolysis of a benzene solution containing [(L)Mo(CO)3(C≡CPh)] (L=η5-C5H5 1; η5-C5Me5 2) and CS2 leads to the formation of dithiopropiolato containing complexes, [(L)Mo(CO)2(η2-S2CC≡CPh)] (L=η5-C5H5 4; L=η5-C5Me5 5). In presence of air, [(η5-C5H5)Mo(CO)3(C≡CPh)] reacts with CS2 to give 4 as the major and [(η5-C5H5)Mo(O)(η3-S2CC≡CPh)] (6) as minor products. Similarly, [(η5-C5Me5)Mo(CO)3(C≡CPh)] reacts with CS2 under aerobic conditions to give compound 5 along with [(η5-C5Me5)Mo(O)(η3-S2CC≡CPh)] (7) as minor product. When solutions of 4 or 5 are photolysed under a constant purge of air, 4 gives 6, and 5 gives 7 in high yields. Room temperature stirring of 5 with [W(CO)5(THF)] forms [η5-C5Me5)Mo(CO)2CS2{W(CO)5}2C≡CPh] (9). All new compounds have been characterised by IR and 1H-NMR spectroscopy and the structures of 4, 6, 7 and 9 have been established crystallographically.