Hydrolysis of Coordinated Diazoalkanes To Yield Side-On 1,2-Diazene Derivatives

Diazoalkane complexes [Ru(η5-C5Me5)(N2CAr1Ar2)(PPh3){P(OR)3}]BPh4 [R = Me (1), Et (2); Ar1 = Ar2 = Ph (a); Ar1 = Ph, Ar2 = p-tolyl (b); Ar1Ar2 = C12H8 (c)] were prepared by allowing chloro complexes RuCl(η5-C5Me5)(PPh3)[P(OR)3] to react with diazoalkane Ar1Ar2CN2 in ethanol. The treatment of compounds 1 and 2 with H2O afforded 1,2-diazene derivatives [Ru(η5-C5Me5)(η2-NH=NH)(PPh3){P(OR)3}]BPh4 (3 and 4) and ketone Ar1Ar2CO. A reaction path involving nucleophilic attack by H2O on the coordinated diazoalkane is proposed. The complexes were characterized spectroscopically (IR and NMR) and by X-ray crystal structure determination of [Ru(η5-C5Me5)(η2-NH=NH)(PPh3){P(OMe)3}]BPh4 (3).Diazoalkane complexes [Ru(eta(5)-C5Me5)(N(2)CAr1Ar2)(PPh3){P(OR)(3)}]BPh4 [R = Me (1), Et (2); Ar1 = Ar2 = Ph (a); Ar1 = Ph, Ar2 = p-tolyl (b); Ar1Ar2 = C12H8 (c)] were prepared by allowing chloro complexes RuCl(eta(5)-(CMe5)-Me-5)(PPh3)[P(OR)(3)] to react with diazoalkane Ar1Ar2CN2 in ethanol. The treatment of compounds 1 and 2 with (HO)-O-2 afforded 1,2-diazene derivatives [Ru eta(5)-C5Me5)(eta(2)-NH-NH)(PPh3){P(OR)(3)}]BPh4 (3 and 4) and ketone Ar1Ar2CO. A reaction path involving nucleophilic attack by H2O on the coordinated diazoalkane is proposed. The complexes were characterized spectroscopically (IR and NMR) and by X-ray crystal structure determination of [Ru(eta(5)-C5Me5)(eta(2)-NH-NH)(PPh3){P(OMe)(3)}]BPh4 (3)