Synthesis of the Five-Coordinate Ruthenium(II) Complexes [(PCP)Ru(CO)(L)][BAr‘₄] {PCP = 2,6-(CH₂P^tBu₂)₂C₆H₃, BAr‘₄ = 3,5-(CF₃)₂C₆H₃, L = η¹-ClCH₂Cl, η¹-N₂, or μ-Cl−Ru(PCP)(CO)}:  Reactions with Phenyldiazomethane and Phenylacetylene

Abstract

Reaction of (PCP)Ru(CO)(Cl) (1) with NaBAr‘4 yields the bimetallic product [{(PCP)Ru(CO)}2(μ-Cl)][BAr‘4] (2). The monomeric five-coordinate complexes [(PCP)Ru(CO)(η1-ClCH2Cl)][BAr‘4] (3) and [(PCP)Ru(CO)(η1-N2)][BAr‘4] (4) are synthesized upon reaction of (PCP)Ru(CO)(OTf) (6) with NaBAr‘4 in CH2Cl2 or C6H5F, respectively. The solid-state structures of 2, 3, and 4 have been determined by X-ray diffraction studies of single crystals. The reaction of 3 with PhCHN2 or PhC⋮CH affords carbon−carbon coupling products involving the aryl group of the PCP ligand in transformations that likely proceed via the formation of Ru carbene or vinylidene intermediates. Density functional theory and hybrid quantum mechanics/molecular mechanics calculations were performed to investigate the bonding of weak bases to the 14-electron fragment [(PCP)Ru(CO)]+ and the energetics of different isomers of the product carbene and vinylidene complexes.

Syntheses and crystal structures of [IrIII{C(CHCO2Et)(dppm)2-κ4 P,C,C′,P′}ClH]Cl·2.75CH2Cl2 and its derivatives, [IrIII{C(CHCO2Et)(dppm)2-κ4 P,C,C′,P′}(CH2CO2Et)Cl]Cl·CH3OH·0.5H2O, [IrIII{C(CHCO2Et)(dppm)2-κ4

“…However, in comparison with a cyclopropane molecule the C4-Ir1-C1 [40.5 (2) ], C4-C1-Ir1 [62.6 (2) ] and C1-C4-Ir1 [76.9 (3) ] angles emphasise a significant distortion of the synthesized threemembered heterocycle. All mentioned geometric features of this strained Ir-C1-C4 metallacycle can be associated with the structural results of the Ru-C-C triangle reported by Zhang et al (2005). Furthermore, the three-membered ring causes a distortion of the octahedral coordination geometry (Table 1).…”

“…By the use of this compound, a targeted synthesis of cyclopropanes or rather heterocyclopropanes, consisting of a transition metal, an electron-donor atom and a carbene carbon, is possible and has been reported several times in the literature (e.g. Nomura et al, 2011;Liu & Yan, 2015;Malisch et al, 1998;Strecker et al, 1991;Zhang et al, 2005, and references cited therein). An electrophilic reaction partner such as a transition metal establishes a nucleophilic attack of the diazo subunit and, according to the choice of the reaction conditions, the elimination of the nitrogen leaving group is supported.…”

“…The stucture of this iridium(III) PCCP complex was completely determined by NMR spectroscopy and X-ray crystallography, but up to now crystallization attempts of the intermediates, 1 and 2, were unsuccessful. With regard to a ruthenium PCP pincer complex, a related cycloaddition was monitored (Zhang et al, 2005). Thereby, the ruthenium transition metal first stabilizes the phenyldiazomethane by coordination.…”

New Oxypyridinate Paddlewheel Ligands for Alkane-Soluble, Sterically-Protected Ru2(II,III) and Ru2(II,II) Complexes

“…The thermal stability of this CH 2 Cl 2 adduct is remarkable in that the Ru–ClCH 2 Cl distance (2.796(6) Å) observed in the X-ray crystal structure of 6-CH 2 Cl 2 is not particularly short relative to what has been observed in the few known Ru­(CH 2 Cl 2 ) structures (Figure ). − The closest analogue to 6-CH 2 Cl 2 is the Ru 2 (II,III) structure reported by Patmore et. al, Ru 2 (O 2 CAr) 4 Cl­(κ 1 -CH 2 Cl 2 ), which possesses a comparable Ru–ClCH 2 Cl distance (2.806(2) Å), but loses its CH 2 Cl 2 ligand in vacuo .…”

Cleavage of the βO4 linkage of lignin using group 8 pincer complexes: A DFT study

“…More popular coordination types of these ligands include PNP, NNN, PCP, NCN, etc [16][17][18][19][20][21][22][23][24][25]. A common structure of these ligands is demonstrated in Fig.…”