PREPARATION OF MONO-(HYDRAZINE) AND BIS(HYDRAZINE) COMPLEXES OF RUTHENIUM(II)

Hydrazine complexes [RuH((RNHNH2)-N-1)L-4]BPh4 1-3, [Ru((RNHNH2)-N-1)( 2)L-4][BPh4](2) 4-6 [R-1 = H, Me, Ph, 4-MeC6H4 or 4-O2NC6H4; L = P(OEt )(3); PPh(OEt)(2) or P(OMe)(3)] were prepared by allowing the hydride species [RuH2L4] to react, first with triflic acid (CF3SO3H) and then with an excess of the appropriate hydrazine. The derivatives [RuH(Me2N NH2){P(OEt)(3)}(4)]BPh4 If, [Ru(eta(1)-OSO2CF3)(Me2NNH2){P(OEt)(3)}(4) ]BPh4 9 and [Ru(eta(2)-Ph-CONHNH2)L-4][BPh4](2) 7,8 [L = P(OEt)(3) or PPh(OEt)(2)] were also obtained. The formulation and geometry in solut ion of the compounds were established by infrared and H-1 and P-31 NMR spectroscopy. The reaction of the bis(nitrile) complexes [Ru((RCN)-C- 2)(2)L-4][BPh4](2) [R-2 = Me or MeC6H4; L = P(OEt)(3) or PPh(OEt)(2)] with hydrazines depends not only on the experimental conditions, but a lso on the nature of the phosphite and the hydrazine used. Thus, nitri lehydrazine [Ru((RNHNH2)-N-1)((RCN)-C-2)L-4][BPh4](2) 10-13 [L = P(OEt )(3) or PPh(OEt)(2)] or amidrazone derivatives [RuH((RN)-N-1=NH)L-4]BP h4, [Ru((RN)-N-1=NH)(2)L-4][BPh4](2) (R-1 = H or Me) were obtained tog ether with the bis(hydrazine) compounds [Ru((RNHNH2)-N-1)(2)L-4][BPh4] (2). Reaction of the arylhydrazine complexes 1-6 and 10-13 with Pb(O2C Me)(4) at -30 degrees C in CH2Cl2 resulted in selective oxidation of t he arylhydrazine ligand giving the aryldiazene derivatives [RuH((RN)-N -1=NH)L-4]BPh4, [Ru((RN)-N-1=NH)(2)L-4]-[BPh4](2) and [Ru((RN)-N-1=NH) ((RCN)-C-2)L-4]-[BPh4](2) (R-1 = Ph, 4-MeC6H4 or 4-O2NC6H4). Treatment of hydrazine NH2NH2 and methylhydrazine MeNHNH2 complexes 1-6 with Pb (O2CMe)(4), instead, afforded the acetate [Ru(eta(2)-O2CMe)L-4]BPh4 de rivatives which were characterised by a crystal structure determinatio n of [Ru(eta(2)-O2CMe){P(OEt)(3)}(4)]BPh4. The co-ordination of ruthen ium is distorted octahedral with approximate C2, symmetry and the acet ate is bidentate.