Search

The N-heterocyclic olefin (NHO) ImMe4＝CH2 (2) (ImMe4＝CH2 = (MeCNMe)2C＝CH2) was employed for the synthesis of the titanium complex 3 derived from an NHO ligand precursor. By reacting 2 with the bis(π–η5:σ–η1-pentafulvene)titanium complex 1a, the terminal ylidic methylene unit of 2 is deprotonated by the quaternary exocyclic carbon atom of one pentafulvene ligand of 1a yielding the titanium complex 3 which bears an anionic NHO ligand (ImMe4＝CH−). 3 was characterized by NMR spectroscopy, single crystal X-ray diffraction and quantum chemical calculations. The latter highlight that 3 is best described as a titanium vinyl complex with significant contribution of the titanium alkylidene resonance structure. [ABSTRACT FROM AUTHOR]

The recently reported bulky N-heterocyclic carbene ITr (ITr = [(HCNCPh3)2C:]) was found to stabilize low-coordinate Ag(i) environments. These electrophilic species were crystallographically identified as the weak solvates [(ITr)Ag(sol)]+ (sol = PhF, MesH or CH2Cl2) and as a solvent-free dimer [(ITr)Ag]22+. The highly electrophilic nature of the [(ITr)Ag]+ cation was further demonstrated by the calculation of a very high methyl ion affinity (MIA) and the synthesis of [(ITr)Ag(PCO)] which features substantial side-on electron donation from a P–C π bond to Ag. [ABSTRACT FROM AUTHOR]

A theoretical study of the desorption of hydrogen from rhombic Group 1 metal hydride dimers reveals a concerted reorganisation of the electron density for the M -H and H -H moieties as the reaction coordinate is traversed and a closed-shell H...H interaction evolves into a covalent H2 bond. The central role played by homopolar dihydrogen bonding in this process is revealed and analysed. [ABSTRACT FROM AUTHOR]