Reactivity and electrochemical behavior of ruthenium dithiolene complexes with coordinatively unsaturated metal centers: cycloaddition and dimerization reactions

Formations and electrochemical behavior of mononuclear and binuclear molybdenum dithiolene complexes with nitrosyl ligands: Evidence for the formation of a coordinatively unsaturated species [Cp∗Mo(NO)(dithiolene)]

“…We have reported that the coordinatively unsaturated cobalt dithiolene complex [CpCo(S 2 C 2 X 2 )] reacts not only with nucleophiles (e.g. diazo compound [35] and azide compound [36]) but also with electrophiles such as DMAD [14,15] and tetracyanoethylene oxide (TCNEO) [37] to afford the coordinatively saturated adducts. We conclude that the [2+2] cycloadduct 1 is produced due to unsaturation of species X.…”

“…The ligand exchange reactions of [Cp * M(Cl)(l-Cl)] 2 (M = Rh, Ir) or [(g 6 -C 6 R 6 )Ru(Cl)(l-Cl)] 2 with a dithiolene ligand have been reported in many cases. These reactions often produce the coordinatively unsaturated species of the monomeric dithiolene complexes [Cp * M(dithiolene)] (M = Rh, Ir) [21b,21c,23,24] or [(g 6 -C 6 R 6 )Ru(dithiolene)] (C 6 R 6 = C 6 H 6 [25], p-C 6 H 4 (Me)(i-Pr) [25], C 6 Me 6 ) [15,22] in a solid state or in a solution. Therefore, we conclude that the unsaturated molybdenum species X is less stable than those of the Rh, Ir and Ru dithiolene complexes.…”

“…The electrochemical oxidations of the mononuclear cobalt dithiolene complex [Cp * Co(dddt)] (dddt = 5,6-dihydro-1,4-dithiin-2,3-dithiolate) [29] and the mononuclear ruthenium dithiolene complex [(C 6 H 6 )Ru{S 2 C 2 (COOMe) 2 }] [15] undergo dimerizations. This process is a unique case, because the reduction of a dimeric dithiolene complex gives a monomer.…”

“…COOMe) [15]. Hidai et al have reported the [2+2] cycloadduct of iridium dithiolene complex [Cp * Ir(S 2 C 2 Z 2 )(C 2 Z 2 )] [16].…”

“…Coordinatively unsaturated metal dithiolene complexes are well-known, and some of them can be dimerized due to their unsaturation. Such dimerizations have been reported in [CpCo(bdt)] (bdt = 1,2-benzenedithiolate) [20], [Cp * Rh (bdt)], [Cp * Rh(mnt)] (mnt = maleonitrile-1,2-dithiolate), [Cp * Rh(dmit)] (dmit = 1,3-dithiole-2-thione-4,5-dithiolate) [21], [(g 6 -C 6 R 6 )Ru(bdt)] and [(g 6 -C 6 R 6 )Ru{S 2 C 2 -(COOMe) 2 }] [15,22].…”