Understanding the M(NHC) (NHC=N-heterocyclic carbene) bond

Jacobsen, Heiko; Correa, Andrea; Poater, Albert; Costabile, Chiara; Cavallo, Luigi

doi:10.1016/j.ccr.2008.06.006

Cited by 680 publications

(202 citation statements)

References 121 publications

Supporting

Mentioning

197

Contrasting

Unclassified

Order By: Relevance

“…38 By contrast, quantitative treatments of the M-P bond in these systems are rare and vastly outnumbered by analyses of the M-C interaction in metal-NHC complexes, which have been intensely scrutinized using a myriad of computational approaches. [72][73][74][75][76][77][78] The most authoritative investigations into M-NHP bonding have been published by Gudat and coworkers. 24,33,79 Together with others in the field, 80 they have analyzed the M-P bond primarily with orbital-based approaches, such as Mulliken and natural population analyses.…”

mentioning

confidence: 99%

Phospha-Fischer Carbenes: Synthesis, Structure, Bonding, and Reactions of Pd(0)− and Pt(0)−Phosphenium Complexes

et al. 2009

View full text Add to dashboard Cite

show abstract

mentioning

confidence: 99%

Phospha-Fischer Carbenes: Synthesis, Structure, Bonding, and Reactions of Pd(0)− and Pt(0)−Phosphenium Complexes

et al. 2009

View full text Add to dashboard Cite

show abstract

“…The steric properties around the metal have been studied in detail, based on the species "PPh 3 " and 14e1, for A and B (see Figure 6). We calculated the percent buried volume (%VBur) by the phosphine-phosphonium ylide ligand of A and the NHC ligand of B [52], using the SambVca2 package developed by Cavallo et al [53,54]. This program examines the first coordination sphere around the metal where the catalytic process takes place, and the buried volume is the measure of the first coordination sphere of the metal held by the donor ligand.…”

Section: Discussionmentioning

confidence: 99%

Olefin Metathesis with Ru-Based Catalysts Exchanging the Typical N-Heterocyclic Carbenes by a Phosphine–Phosphonium Ylide

2017

Self Cite

View full text Add to dashboard Cite

Density functional theory (DFT) calculations have been used to describe the first turnover of an olefin metathesis reaction calling for a new in silico family of homogenous Ru-based catalysts bearing a phosphine-phosphonium ylide ligand, with ethylene as a substrate. Equal to conventional Ru-based catalysts bearing an N-heterocyclic carbene (NHC) ligand, the activation of these congeners occurs through a dissociative mechanism, with a more exothermic first phosphine dissociation step. In spite of a stronger electron-donating ability of a phosphonium ylide C-ligand with respect to a diaminocarbene analogue, upper energy barriers were calculated to be on average ca. 5 kcal/mol higher than those of Ru-NHC standards. Overall, the study also highlights advantages of bidentate ligands over classical monodentate NHC and phosphine ligands, with a particular preference for the cis attack of the olefin. The new generation of catalysts is constituted by cationic complexes potentially soluble in water, to be compared with the typical neutral Ru-NHC ones.

show abstract

“…The radius of the sphere around the origin placed 2 Å below the metal center was set to 3.5 Å, while for the atoms we adopted the Bondi radii scaled by 1.17, and a mesh of 0.1 Å was used to scan the sphere for buried voxels. The steric maps were evaluated with a development version of the SambVca package [46,60].…”

Section: Computational Detailsmentioning

confidence: 99%

In Silico Switch from Second- to First-Row Transition Metals in Olefin Metathesis: From Ru to Fe and from Rh to Co

et al. 2017

Self Cite

View full text Add to dashboard Cite

Density functional theory (DFT) calculations have been used to investigate the behavior of different transition metals from Groups 8 (Fe and Ru) and 9 (Co and Rh) in an already well-known catalytic mechanism, which is based on an Ru(SIMes)(PPh 3 )Cl 2 =CH(Ph) complex. As expected, Ru has proven to perform better than their Fe, Co, and Rh counterparts. Even though the topographic steric maps analysis shows no difference in sterical hindrance for any of the metal centers, geometrically, the Fe-based species show a high rigidity with shorter and stronger bonds confirmed by Mayer Bond Orders. The systems bearing Co as a metallic center might present a reactivity that is, surprisingly, too high according to conceptual DFT, which would consequently be a drawback for the formation of the fundamental species of the reaction pathway: the metallacycle intermediate.

show abstract

Understanding the M(NHC) (NHC=N-heterocyclic carbene) bond

Cited by 680 publications

References 121 publications

Phospha-Fischer Carbenes: Synthesis, Structure, Bonding, and Reactions of Pd(0)− and Pt(0)−Phosphenium Complexes

Phospha-Fischer Carbenes: Synthesis, Structure, Bonding, and Reactions of Pd(0)− and Pt(0)−Phosphenium Complexes

Olefin Metathesis with Ru-Based Catalysts Exchanging the Typical N-Heterocyclic Carbenes by a Phosphine–Phosphonium Ylide

In Silico Switch from Second- to First-Row Transition Metals in Olefin Metathesis: From Ru to Fe and from Rh to Co

Contact Info

Product

Resources

About