Synthesis and structure of (.eta.-C5H5)W(PPh3)(CO)(CSPh): transformation of a thiocarbonyl ligand into a carbyne ligand

The arylation reaction (eta-C/sub 5/H/sub 5/)W(PPh/sub 3/)(CO)(CS)I + LiPh ..-->.. (eta-C/sub 5/H/sub 5/)W(PPh/sub 3/)(CO)(CSPh) + LiI (5) reduces the multiple bonding in the terminal CS ligand of (eta-C/sub 5/H/sub 5/)W(PPh/sub 3/)(CO)(CS)I to a C-S single bond in the carbyne product. The previously reported alkylation (Ph/sub 2/PCH/sub 2/CH/sub 2/PPh/sub 2/)/sub 2/W(CO)(CS) + MeOSO/sub 2/F ..-->.. (Ph/sub 2/PCH/sub 2/CH/sub 2/PPh/sub 2/)/sub 2/W(CO)(CSMe)/sup +/SO/sub 3/F/sup -/ (1), and Lewis adduct formation reactions of terminal CS groups in electron-rich complexes presumably also yield CSR carbyne complexes. These results suggest that similar adducts of terminal CO ligands could be reasonable intermediates in catalytic reactions of carbon monoxide which lead to the cleavage of the carbon-oxygen triple bond. A single crystal of (eta-C/sub 5/H/sub 5/)W(PPh/sub 3/)(CO)(CSPh) approx. 0.2 x 0.15 x 0.4 mm was chosen for the x-ray diffraction study. The average distance from the tungsten to the cyclopentadienyl carbon atoms is 2.366 A. Data were given for the other ligands. 1 figure. (DP)