Abstract
Reactions of the thiolate‐bridged diruthenium complex [Ru(py^bu^S~4~)]~2~ (1) {py^bu^S~4~^2−^ = 2,6‐bis[(3,5‐di‐tert‐butyl‐2‐sulfanylphenyl)thiomethyl]pyridine(2−)} with small‐molecule ligands L afforded the corresponding mononuclear complexes [Ru(L)(py^bu^S~4~)] [L = H^−^ (2); CH~3~CN (3); NH~3~ (4); CO (5); N~2~H~4~ (6); PMe~3~ (7); N~3~^−^ (8)]. The molecular structures of 3, 4, and 5 exhibit pseudooctahedral geometry with two thiolate and two thioether donor atoms in a trans configuration. Complexes 2−8 exhibit a quasi‐reversible, one‐electron redox wave of the Ru^II^/Ru^III^ couple in the region between E~1/2~ = +0.214 and +0.460 V vs. NHE. Complex 1 reacts reversibly with N~2~ (60 bar) at 40 °C to give the labile dinitrogen complex [Ru(N~2~)(py^bu^S~4~)] (9). Complex 9 can also be obtained from the reaction between 3 and N~2~ (20 bar) at room temperature. Treatment of 4 with NO afforded the labile 19‐valence‐electron species [Ru(NO)(py^bu^S~4~)] (10) in solution, which could subsequently be converted to 9 upon highpressure reaction with N~2~ (20 bar). In contrast, the analogous reaction of 4 with NOBF~4~ results in the formation of the oxidized complex [Ru(NH~3~)(py^bu^S~4~)]BF~4~ (11), the structure of which was confirmed by X‐ray structure analysis. The carbonyl complex [Ru(CO)(py^bu^S~4~)] (5) could be reversibly protonated at the thiolate sulfur atom to give [Ru(CO)(py^bu^S~4~H)]BF~4~ (12). UV irradiation of 5 and 12 under N~2~ at −80 °C produced the short‐lived species 9 and 13, respectively, which were identified spectroscopically. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)