Insertion of CS 2 into a metal acetylide bond and conversion of the bonding mode of S 2CCCPh from η 2 to η 3

Abstract

Photolysis of a benzene solution containing [(L)Mo(CO) 3(CCPh)] (L=η 5-C 5H 5 1; η 5-C 5Me 5 2) and CS 2 leads to the formation of dithiopropiolato containing complexes, [(L)Mo(CO) 2(η 2-S 2CCCPh)] (L=η 5-C 5H 5 4; L=η 5-C 5Me 5 5). In presence of air, [(η 5-C 5H 5)Mo(CO) 3(CCPh)] reacts with CS 2 to give 4 as the major and [(η 5-C 5H 5)Mo(O)(η 3-S 2CCCPh)] ( 6) as minor products. Similarly, [(η 5-C 5Me 5)Mo(CO) 3(CCPh)] reacts with CS 2 under aerobic conditions to give compound 5 along with [(η 5-C 5Me 5)Mo(O)(η 3-S 2CC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 [η 5-C 5Me 5)Mo(CO) 2CS 2{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.