Protonation of a Ruthenium Vinylidene Complex with a NO Ligand Leading to Ruthenium Vinyl Complexes

Treatment of a ruthenium vinylidene complex bearing a bent-type NO ligand, RuCl(NO)(PPh3)2{CCH(C6H4Me)} (1), with protic acids gave rise to the ruthenium vinyl complexes RuCl(X){(Z)-CHCH(C6H4Me)}(PPh3)2(NO) (X = Cl (2a), O2CCF3 (2b), FBF3 (2c)) with concomitant transformation to linear-type NO. This indicates unusal protonation at the vinylidene α-carbon and anion-part coordination of the protic acids to the ruthenium atom at the trans position to the resulting vinyl group. The coordinated BF4 moiety of 2c was easily replaced to be a counteranion by MeCN solvent molecules, yielding [RuCl{(Z)-CHCH(C6H4Me)}(NCMe)(PPh3)2(NO)]BF4 (3).