MULTIPLE BONDS BETWEEN MAIN-GROUP ELEMENTS AND TRANSITION METALS .165. RHENIUM(V) OXO COMPLEXES WITH BIDENTATE SCHIFF-BASES - STRUCTURES AND CATALYTIC APPLICATIONS

Reaction of [NBu4][ReOCl4] (1) with bidentate salicylidene amine Ligan ds (salen = HL) (2a-c) leads to the formation of monomeric octahedral rhenium(V) compounds of formula [ReOCl(L)(2)] (3a-c). Spectroscopic da ta indicate asymmetric arrangement of the ligands in the complexes. Th is is confirmed by the X-ray crystal structures of 3b and 3c. Complexe s 3a, b have been tested as catalysts for the epoxidation of cycloocte ne. No evidence for decomposition of the catalysts is observed during the reaction (as in the case for tri-and tetradentate salen complexes) . No undesired byproducts are formed in the catalytic reactions.