SURFACE ORGANOMETALLIC CHEMISTRY OF TANTALUM: APPLICATION TO THE METATHESIS OF ALKANES CATALYZED BY A TANTALUM HYDRIDE SUPPORTED ON SILICA

摘要

Heterogeneous catalysts are widely used in industry because they can usually be conveniently separated from the reaction medium. From a fundamental point of view, it is always difficult to define and control the real coordination sphere and then to determine the various elementary steps of a catalytic reaction. On the contrary, homogeneous catalysis has been developed on the rules of Molecular Organometallic Chemistry, which affords a better understanding of what are the active species and the elementary steps of a process. Surface Organometallic Chemistry (SOMC) is aimed at the preparation of highly reactive well-defined supported organometallic species which would obey the concepts and the rules of Molecular Organometallic Chemistry. The formation of such supported organometallic species usually involves the reaction of molecular complexes with functional groups of a surface. Surface Organometallic Chemistry found application in the field of the activation and valorisation of alkanes which has been the subject of numerous studies during the last two decades [1,2]. The transformation of alkanes may involve the activation of C-H or C-C bonds or both [3-5].