Collect. Czech. Chem. Commun. 1993, 58, 461-473

On the Electrochemical, Spectral and Photochemical Properties of Cyano-Nitrosyl Complexes. A Comparison between Iron and Ruthenium Analogues

Jan Fiedler

J. Heyrovský Institute of Physical Chemistry and Electrochemistry, Academy of Sciences of the Czech Republic, 182 23 Prague 8, Czech Republic


First order rate constant of cyanide splitting from one-electron product of the nitropruside ion reduction was determined using a.c. polarography (k = 350 s-1 in CH3CN). [Ru(CN)5(NO)]2- ion is reduced reversibly (E1/2 = -1.04 V, k0 = 4.86 . 10-3 m s -1 in CH3CN; E1/2 = -0.39 V in H2O) with one electron. IR and EPR study indicates dimerization of the reduction product in solution but no cyanide splitting from electrogenerated [Ru(CN)5(NO)]3- was detected. Further reduction of [Ru(CN)5(NO)]3-, with consumption of protons occurs in aqueous media. Efficient photochemical reactions of [Fe(CN)4(NO)]2- with O2, KMNO4 and pyridine take place when the complex is excited at the metal-to-nitrosyl charge transfer band.