Stable singlet carbenes as mimics for transition metal centers

Redox-induced umpolung of transition metal carbenes.

Metal carbene complexes have been at the forefront of organic and organometallic synthesis and are instrumental in guiding future sustainable chemistry efforts. While classical Fischer and Schrock type carbenes have been intensely studied, compounds that do not fall within one of these categories have attracted attention only recently. In addition, applications of carbene complexes rarely take ...

iV-Heterocyclic carbenes and their application as ligands for transition metal mediated synthesis

New Predictions for Singlet-Trlplet Gaps of Substituted Carbenes

of niobium clusters with cyclohexene and 1,3-~yclohexadiene makes both the energy and the entropy contribution to the free energy even more favorable for the dehydrogenation reaction. These two factors, the lack of aromatic stability and the increased entropy change, appear to lessen the effect of the relative stability of the Nbs and Nb,,, structures on their reactivity with cyclohexene and 1,...

Bonding in Transition-Metal Methylene Complexes. 3. Comparison of Cr and Ru Carbenes; Prediction of Stable LnM(CXY) Systems’

The electronic structure of the lowest carbene state of a representative early-transition-metal complex, CrCH2+ (6A1 symmetry), has been examined by using ab initio techniques. Its properties reveal a complex with a single u-donor bond from singlet CH2 to high-spin (d5) Cr+ and no *-back-bond, resulting in a low bond energy (38.7 kcal/mol) and a large carbenealkylidene state splitting (18.8 kca...

Transition-Metal Single Atoms in a Graphene Shell as Active Centers for Highly Efficient Artificial Photosynthesis