Triply bridged dinuclear ruthenium complexes bearing alkylbis(2-pyridylmethyl)amine in the mixed-valence state of Ru(ii)–Ru(iii)

Abstract

Five diruthenium complexes in the mixed-valence state of Ru(ii)–Ru(iii), triply bridged by halogeno and methoxido ligands, were newly synthesized and compared.

Halogeno Ligand‐Substitution Reactions of Ruthenium Complexes Bearing Ethylbis(2‐pyridylmethyl)amine to Synthesize New Complexes

“…In acetone containing hydrochloric acid, one‐electron reduction of [ 1 Cl ] induced chlorido dissociation and dimerization to give a diruthenium complex bridged by three chlorido ( n = 1.5). [6a], [6b] The number of dissociating chlorido ligand through reduction reaction was controlled by the kind of solvent. The hydrophobic chloroform allowed dissociation of two out of three chlorido ligands to afford fac ‐[RuX(L) 2 (ebpma)]‐type complexes, on the other hand, the presence of water induced substitution of all the three halogeno ligands of [ 1 X ] to give fac ‐[Ru(L) 3 (ebpma)]‐type complexes.…”

“…Therefore, [ 4 ](PF 6 ) 2 could also be formed through a reaction of [ 3 Cl ]PF 6 in water/acetonitrile by removing the remaining one last chlorido ligand. After [ 1 Cl ] was one‐electron reduced, mononuclear or dinuclear species ( n = 0.5, 1, and/or 1.5[6b]) could be formed and were coordinated by Lewis bases such as acetonitrile, pyridine, or ammonia, affording mononuclear ruthenium(II) complexes. The presence of bridging ligand such as chrorido and methanol afforded dinuclear ruthenium frameworks.…”

“…The presence of bridging ligand such as chrorido and methanol afforded dinuclear ruthenium frameworks. [6a], [6c] From only one starting material [ 1 X ], which is formed by the simple reaction of ruthenium chloride salt, RuCl 3 · n H 2 O, with ebpma, halogeno‐substituted species to Lewis bases in solutions in stepwise manners, n = 1–3, could be systematically obtained.…”

“…As reported earlier, in ethanol containing acetonitrile, dissociation of all the three chlorido ligands was induced via one‐electron reduction of fac ‐[Ru III Cl 3 (ebpma)] ([ 1 Cl ]), resulting in the formation of triacetonitrileruthenium(II) complex, fac ‐[Ru II (NCCH 3 ) 3 (ebpma)] 2+ ([ 4 ] 2+ ) . In methanol or acetone containing hydrochloric acid, dimerization occurred to afford triply bridged diruthenium complexes in the mixed‐valent state of Ru(II)‐Ru(III), [{Ru II,III (ebpma)} 2 (µ‐Cl) m (µ‐OCH 3 ) 3‐ m ] 2+ ( m = 1–3), via the corresponding Ru(II)‐Ru(II) species and coordination of chloride or methoxide in the solutions under atmospheric conditions . In this paper, the strategies for syntheses of new complexes having desired co‐existing ligands by dissociation and substitution of halogeno ligands are reported, starting from fac ‐[Ru III X 3 (ebpma)] ([ 1 x ]; X = Cl, Br).…”

“…Materials . RuCl 3 · n H 2 O (content of Ru, 40.11 wt.‐%) was purchased from Furuya Kinzoku Inc. Ethylbis(2‐pyridylmethyl)amine (ebpma), fac ‐[Ru III Cl 3 (ebpma)] ([ 1 Cl ]), fac ‐[Ru III Br 2 (ebpma)] ([ 1 Br ]),[6a] and fac ‐[Ru II (NCCH 3 ) 3 (ebpma)](PF 6 ) 2 ([ 4 ](PF 6 ) 2 ) were prepared according to the literature procedures.…”