Reactions of a dinuclear tungsten complex containing an O-co-ordinated bridging ketene with various heterocumulenes

Treatment of the dinuclear O-co-ordinated ketene complex W2Cp2(CO)(5)(mu-et a(1):eta(2)-CH2CO) (Cp=eta(5)-C5H5) with PhCH2NCS afforded the dark red bri dging thioketene complex W2Cp2(CO)(5)(mu-eta(3)-SC=CH2). Reaction of the la tter with HBF4 gave the stable cationic product [W2Cp2(CO)(5)(mu-SCMe3)]BF4 by addition of a proton to the terminal carbon of the thioketene group. In the reaction of W2Cp2(CO)(5)(mu-eta(1):eta(2)- CH2CO) with CS2 cleavage of one CS bond is accompanied by insertion of the resulting sulfur atom into the tungsten-acyl bond to afford W2Cp2(CO)(5)(CS)(mu-CH2COS). The Cp' analo gue (Cp'=eta(5)-C5H4Me) was also prepared. The reaction of the trithiocarbo nate S=C(SCH2)(2) with W2Cp2(CO)(5)(mu-eta(1):eta(2)- CH2CO) afforded the c arbene complex W2Cp2(CO)(5)[C(SCH2)(2)](mu-CH2COS), and with allene gave th e allylic complex W2Cp2(CO)(5)(mu-eta(1):eta(3)- CH2COC3H4). Those of the c omplexes have been characterized by single crystal X-ray diffraction analys is.