Base-Induced Dehydrogenation of Ruthenium Hydrazine Complexes

Treatment of [RuCl(PP3 iPr)]+Cl– (PP3 iPr = P(CH2CH2P i Pr2)3) with hydrazine, phenylhydrazine, and methylhydrazine afforded side-on bound hydrazine complexes [RuCl(η2-H2N-NH2)(η3-PP3 iPr)]+, [RuCl(η2-H2N-NHPh)(η3-PP3 iPr)]+, and [RuCl(η2-H2N-NHMe)(η3-PP3 iPr)]+. The analogous reactions of [RuCl2(PP3 Ph)] (PP3 Ph = P(CH2CH2PPh2)3) with hydrazine, phenylhydrazine, and methylhydrazine afforded end-on bound hydrazine complexes [RuCl(η1-H2N-NH2)(PP3 Ph)]+, [RuCl(η1-H2N-NHPh)(PP3 Ph)]+, and [RuCl(η1-H2N-NHMe)(PP3 Ph)]+. Treatment of parent hydrazine complex [RuCl(N2H4)(PP3 iPr)]+ with strong base afforded the dinitrogen and dihydride complexes [Ru(N2)(PP3 iPr)] and [RuH2(PP3 iPr)]. Treatment of phenylhydrazine complex [RuCl(NH2NHPh)(PP3 iPr)]+ with strong base afforded the hydrido ruthenaindazole complex [RuH(η2-NHNC6H4)(η3-PP3 iPr)] while similar treatment of methylhydrazine complex [RuCl(NH2NHMe)(PP3 iPr)]+ afforded the hydrido methylenehydrazide complex [RuH(NHNCH2)(PP3 iPr)]. Treatment of the hydrazine complexes [RuCl(NH2NHR)(PP3 Ph)]+ (R = H, Ph, Me) with strong base afforded the dinitrogen complex [Ru(N2)(PP3 Ph)].