Kinetische untersuchungen über reaktionen von metall-komplexen : XVI. Substitutionsreaktionen von metallcarbonylkomplexen des chroms, molybdäns und wolframs; einige neue kinetische und mechanistische aspekte

Abstract

Metal carbonyls today are classical representatives of coordination compounds, thanks primarily to the pioneering work of Walter Hieber and his school. One of their most characteristic properties is that they undergo substitution reactions with a great number of Lewis bases L. In these reactions, either one or several CO ligands (in very rare cases all CO ligands) are replaced. Substitution reactions of the type: ▪ are known for practically all metal carbonyls. Detailed studies have been made particularly on the reactions of chromium, molybdenum and tungsten carbonyl compounds, including kinetic and mechanistic investigations. The present review is concerned with recent results in this area with special emphasis on carbene carbonyl complexes. The point is made that the reaction possibilities shown by the compounds of general composition M(CO) 6, M(CO) 5L, M(CO) 4LL′, M(CO) 4(LL) and M(CO) 3(LLL) (M = Cr, Mo, W; L (or L′) = unidentate, LL = bidentate, LLL = tridentate ligand) are important not only for synthetic purposes, but also exhibit interesting mechanistic characteristics.