Binuclear organometallic compounds. Part V. Insertion into M–C and H–C bonds of co-ordinatively unsaturated transition-metal fragments: synthesis of group VIAmetal cyclopentadienyltricarbonyl metallates (germanium and tin) and hydrides

Abstract

The reactions of Me3M1–C5H5(M1= Si, Ge, and Sn) with low oxidation state, co-ordinatively unsaturated transition metal substrates are divided into: Class (I), oxidative addition–elimination; Class (II), oxidative cleavage; and Class (III), reactions as ligands. Class (I) systems are described in detail for M1= Ge and Sn reacting with M2(MeCN)3(CO)3(M2= Cr, Mo, and W), to yield M2(π-C5H5)(Me3M1)(CO)3. Reactivity decreases for a given M1 in the sequence Cr > Mo ≈ W, and Sn > Ge Si (unreactive) for a given M2. The same Group VIA reactivity order is observed for the related reactions of C5H5 and M2(MeCN)3(CO)3 to afford M2H(π-C5H5)(CO)3; these are recommended as the most convenient of the available syntheses of such metal hydrides. Optimal reaction conditions are prescribed.