Reactivity of vinylidene complexes of ruthenium with hydrazines and hydroxylamines

Abstract

Vinylidene complexes [Ru(η⁵-C₅H₅){CC(H)R}(PPh₃)L]BPh₄ (1, 2) [L = P(OMe)₃, P(OEt)₃; R = Ph, p-tolyl, Bu^t, H] react with hydrazine R1NHNH₂ (R1 = H, Me, Ph) to afford nitrile derivatives [Ru(η⁵-C₅H₅)(NCCH₂R)(PPh₃)L]BPh₄ (3, 4) and amine R1NH₂. Hydroxylamine NH₂OH also reacts with vinylidenes 1, 2 to yield nitrile derivatives 3, 4 and H₂O. Studies with ¹⁵N-labeled hydrazine and DFT calculations allowed a reaction path to be proposed. The complexes were characterized by spectroscopy (IR, ¹H, ³¹P, ¹³C and ¹⁵N NMR) and by X-ray crystal structure determination of [Ru(η⁵-C₅H₅)(NCCH₂Ph)(PPh₃){P(OEt)₃}]BPh₄ (4a).