The reaction of [RuCl(PMe2Ph)2(Cp)] with ethyne and TlBF4 in dichloromethane leads to [Ru(η2-HC≡CH)-(PMe2Ph)2(Cp)][BF4] (2), an unusual η2-alkyne complex of a d6 metal center. This ethyne complex smoothly rearranges to its vinylidene isomer, [Ru(C=CH2)(PMe2Ph)2(Cp)] [BF4] (4), above ca. 60 °C in acetone solution. The η2-ethyne to vinylidene conversion can also be carried out by deprotonation of 2 to give [Ru(C≡CH)(PMe2Ph)2(Cp)] (3), followed by protonation of 3 to give exclusively vinylidene isomer 4. Structures of both 2 and 4 were determined by X-ray diffraction. Aside from the difference in the geometry of the C2H2 ligands, the structures are nearly identical. Crystal data with Mo kα(λ= 0.7107 Å) radiation at 297 K are as follows: 2, C23H29BF4P2Ru, a = 23.099 (3) Å, b = 9.203 (2) Å, c = 11.344 (3) Å, orthorhombic space group Pca21, (No. 29), Z = 4, R = 0.054, Rw = 0.074; 4, C23H29BF4P2Ru, a = 23.270 (3) Å, b = 9.290 (1) Å, c = 11.3659 (8) Å, orthorhombic space group Pca21 (No. 29), Z = 4, R = 0.035, Rw = 0.044.
|Number of pages||6|
|Journal||Journal of the American Chemical Society|
|State||Published - Jul 1 1992|
ASJC Scopus subject areas
- Chemistry (all)
- Colloid and Surface Chemistry