Catalytic reduction of carbon dioxide by a zinc hydride compound, [Tptm]ZnH, and conversion to the methanol level.

The zinc hydride compound, [Tptm]ZnH, may achieve the reduction of CO by (RO)SiH (R = Me, Et) to the methanol oxidation level, (MeO)Si(OR), the formate species, HCOSi(OR). However, because insertion of CO into the Zn-H bond is more facile than insertion of HCOSi(OR), conversion of HCOSi(OR) to the methanol level only occurs to a significant extent in the absence of CO.

Molecular structures of tris(1-tert-butyl-2-mercaptoimidazolyl)hydroborate complexes of titanium, zirconium and hafnium.

Cyclopentadienyl and tris(pyrazolyl)hydroborate have found much use as supporting ligands in the chemistry of titanium, zirconium and hafnium, especially with respect to applications involving olefin polymerization catalysis. In contrast, closely related tris(1-alkyl-2-mercaptoimidazolyl)hydroborate, [Tm], ligands have so far found little application to the chemistry of these elements, despite the fact that such ligands are currently used extensively in coordination chemistry. In view of the fact that a substituent in the 2-position exerts a direct influence on the steric environment of the metal center, we report here the application of the sterically demanding tris(1-tert-butyl-2-mercaptoimidazolyl)hydroborate [Tm] ligand to these metals.