Spectroscopic and electrochemical properties of a new nitrosyl-complex of Ru(II):: trans-[Ru(NO){(CH3CH2)2PCH2CH2P(CH2CH3)2}2Cl](PF6)2

A new ruthenium nitric oxide complex with the bidentate phosphine, 1,2-bis(diethylphosphino)ethane (depe), has been synthesized and characterized by UV-Vis, infrared, EPR, NMR, electrochemical techniques and X-ray structure determination. The electronic spectrum showed a typical band of dpi --> ppi* charge-transfer (CT) transition, assigned to Ru(II)-NO transition, and the vibrational spectrum exhibited a peak of nitrosyl ligand at (v(NO)=1851 cm(-1)) model structure for this complex has been proposed based on H-1, H-1{P-31}, P-31{H-1}, C-13{H-1}, COSY (HH)-H-1-H-1{P-31}, J-Resolved, HSQC, HMBC, HSQC H-1-C-13{P-31} and H-1-C-13 HSQC/H-1-H-1 TOCSY spectral data, and confirmed by X-ray diffraction. The nitrosonium character for the NO ligand become evident through both electron paramagnetic resonance and X-ray data (angle Ru-N-O = 177.4(3)). The reversible monoeletronic process at E-1/2 = 0.040 V versus SHE was assigned to the ligand NO+/NO. redox couple. Under treatment with Cd(Hg) solutions containing the [Ru(NO)(depe)(2)Cl](PF6)(2) yields a signal in the EPR spectrum (g(perpendicular to) = 1.99 and g(parallel to) = 1.88) which fitted quite well with the simulated spectra of coordinated NO. species. (C) 2002 Elsevier Science B.V. All rights reserved.