Substitution and redox reactions of mono- and dinuclear ruthenium complexes containing the pyN2H2S22- ligand [pyN2H2S22-=2,6-bis(2-mercaptophenylaminomethyl)pyridine(2-)]

In quest of ruthenium complexes having [RuN3S2] cores, a non-flexible configuration, trans-thiolate donors and exchangeable coligand L, [Ru(L)(pyN2H2S2)] complexes have been synthesized [pyN2H2S22-=2,6-bis(2-mercaptophenylaminomethyl)pyridine(2-)]. Treatment of [RuCl2(CH3CN)4] with pyN2H2S22- gave [Ru(py)(pyN2H2S2)] (1). The pyridine coligand in 1 proved to be labile and could be substituted by either CO or DMSO under normal conditions to give [Ru(CO)(pyN2H2S2)] (2) and [Ru(DMSO)(pyN2H2S2)] (3), respectively. Alternatively, 2 could be obtained directly from [RuCl2(CH3CN)4] and pyN2H2S22-in the presence of CO, whereas the reaction in the absence of CO gave the dinuclear [Ru(pyN2H2S2)]2 (8). Treatment of either 2 or 3 with NOBF4 afforded [RuIII(CO)(pyN2H2S2)]BF4 ([4]BF4) and [Ru(NO)(pyN2H2S2)]BF4 ([5]BF4), respectively. Treatment of [5]BF4 with either NEt4N3 or N2H4 afforded the amide [Ru(NO)(pyN2HS2)] (6) and the hydrazine [Ru(N2H4)(pyN2H2S2)] (7), respectively. Treatment of the dinuclear 8 with either one or two equivalents of NOBF4 afforded the mixed-valence diruthenium (II,III) [RuIIIRuII(pyN2H2S2)2]BF4 ([9]BF4) and the diruthenium (III) [RuIIIRuIII(pyN2H2S2)2](BF4) 2 {[10](BF4)2}, respectively. The diruthenium (III) complex [10](BF4)2 is diamagnetic, which can be ascribed to spin–spin pairing between the two RuIII atoms. A preliminary structure determination of [10](BF4)2 supports this observation, indicating a single bond between the two RuIII atoms. Novel diruthenium complex of this type could be synthesized more generally by treatment of [RuCl3(MeSPh)3] with pyN2H2S22-. All complexes were characterized by spectroscopic methods and elemental analysis. The cations [9]+ and [10]2+ were characterized by X-ray structure analysis.

In quest of ruthenium complexes having [RuN3S2] cores, a non-flexible configuration, trans-thiolate donors and exchangeable coligand L, [Ru(L)(pyN2H2S2)] complexes (L = CO, NO, N2H4, DMSO and pyridine) have been synthesized and completely characterized. A series of thiolate-bridged diruthenium(II) complexes [RuIIRuII(pyN2H2S2)2], mixed-valence diruthenium (II,III) [RuIIRuIII(pyN2H2S2)2]BF4, and diruthenium (III) [RuIIIRuIII(pyN2H2S2)2](BF4) have been isolated and completely characterized. The crystal structure of the novel dimeric [RuIIIRuIII(pyN2H2S2)2](BF4)2 and the NMR are also discussed. The later is diamagnetic, which is assignable to a spin–spin pairing as well as a single bond between the two RuIII centers.Figure optionsDownload as PowerPoint slide