87102-01-0Relevant academic research and scientific papers
Transition-metal-cyanocarbon chemistry. 2. Cyanoacetylene insertions into the metal-hydrogen bond of (η5-C5H5)(CO)3MH (M = Mo, W) complexes. Formation of phosphorus ylide complexes and the structure of (η5-C5H5)(CO)2Mo[η 2-C(CN)PPh3CHCN]
Scordia, Henri,Kergoat, René,Kubicki, Marek M.,Guerchais, Jacques E.,L'Haridon, Paul
, p. 1681 - 1687 (2008/10/08)
Reactions of the hydride complexes (η5-C5H5)(CO)3MH (M = Mo, W) with cyanoacetylene, HC≡CCN, and dicyanoacetylene, NCC≡CCN, in tetrahydrofuran solution gave the corresponding insertion compounds (η5C5H5)(CO) 3M(σ-CR≡CHCN) (M = Mo, R = CN; M = W, R = H, CN). Irradiation of these complexes with PPh3 afforded the products (η5-C5H5)(CO)2M(η 2-CRPPh3CHCN) (M = Mo, R = CN; M = W, R = H, CN) containing a phosphorane ligand. Rearrangement of the substitution complex (η5-C5H5)-(CO)2PPh 3W(σ-CH≡CHCN) to (η5-C5H5)(CO)2W(η 2-CHPPh3CHCN) upon irradiation suggests that the formation of ylide complexes from the insertion products may proceed via an initial attack of phosphine on the metal center. (η5C5H5)(CO)2Mo[η 2-C(CN)PPh3CHCN] has been characterized by an X-ray structure analysis: monoclinic, P21/n, a = 13.691 (4) A?, b = 15.892 (4) A?, c = 11.557 (5) A?, β = 100.96 (3)° , Z = 4, R = 0.028, Rw = 0.039. This structure, together with the spectroscopic data (IR, 1H and 13C NMR), suggests that the formal negative charge induced by ylide formation is localized on the metal center.
