Spectroscopic and Computational Studies of the Ligand Redox Non-Innocence in Mono- and Binuclear Ruthenium Vinyl Complexes

Abstract

A combination of IR spectroelectrochemistry and DFT calculations has been used to demonstrate that the vinyl ligands in the complexes [Ru(CHdCHC 6 H 4 Me-4)Cl(CO)-(PMe 3 ) 3 ] and [{RuCl(CO)(PMe 3 ) 3 } 2 (μ-CHdCHC 6 H 4 CHd CH)] are redox noninnocent, and one-electron oxidation results in radical cations that are best described in terms of metal-stabilized organic radicals.

Syntheses, structures and redox properties of tris(pyrazolyl)borate-capped ruthenium vinyl complexes

“…The 'prime' nomenclature is used to distinguish the computational and experimental systems. We have found on previous occasions that B3LYP / 3-21G* generally gives computational results which are in good agreement with experimentally determined structural and spectroscopic properties for both ruthenium acetylide [20] and vinyl [28] complexes. However, in the case of [4a´] n (n = 0, +1, +2), [4b´] n (n = 0, +1),…”

“…The metal center in 3a exhibits a distorted octahedral geometry, consistent with previous examples [28,46]. The vinyl ligand is co-planar with the CO moiety (C(23)-…”

“…It has now been firmly established that ruthenium alkynyl complexes Ru(CCR)(PP)Cp´ (P = phosphine, PP = bis(phosphine); Cp´ = Cp, Cp*) [13][14][15] and Ru(X)(CCR´´)(PP) 2 made progressively lower and lower in energy (e.g. 1-naphthyl, 9-anthryl, ethynylphenyl) [18][19][20], and when incorporated into bridging ligands spanning two strongly electron-donating ruthenium fragments [21][22][23][24][25][26][27][28]. 6 The complexes Ru(CH=CHR´´)(Cl)(CO)(PR 3 ) 2 L, which are readily prepared by insertion of an alkyne into the Ru-H bond in RuHCl(CO)(PR 3 ) n (n = 2, 3) [29] offer an entry point to a wide range of vinyl complexes through facile substitution reactions of the supporting phosphine and chloride ligands by a wide range of neutral and anionic mono and bidentate ligands (Scheme 1) [30,31].…”

“…The five-coordinate species are convenient precursors to a range of derivatives through ligand substitution reactions [37][38][39][40][41][42][43][44], giving considerable scope to tune the metal-ligand coordination sphere. [18] and Ru(CH=CHR)(Cl)(CO)(PMe 3 ) 3 [28,46].…”

Synthesis, Structure and Electrochemical Properties of Triarylamine Bridged Dicobaltdicarbon Tetrahedrane Clusters

“…These systems are ideal candidates for the study of intramolecular electron transfer processes [5][6][7], which in turn underpin applications in catalysis [8], energy science [9, 10] and molecular electronics [11,12] whilst also illustrating fine details of electronic structure arising from the often unexpected redox activity of the supporting or bridging ligands [13][14][15][16][17]. Whilst the considerable majority of studies in this area have focussed on bis(monometallic) complexes in which two metal centres are linked through a (usually -conjugated) bridging ligand [18,19], systems derived from organic electrophores [20] and cluster systems [21] have not been overlooked.…”