| 摘要 |
Penta- and hexa-coordinated, bridged ruthenium and osmium catalysts of the formulawherein Me is ruthenium or osmium; L1 and L2 are neutral ligands having electron donor properties;X is an anionic ligand; Y is oxygen or sulphur; A is a direct bond, C1-C4alkylene or C2-C4alkylidene;Z is a direct bond, oxygen, sulphur or the groupswherein R1 and R2 are hydrogen or hydrocarbon radicals; their preparation and their us in the synthesis of polymers, in the ring-closure metathesis of diolefins, in the cross metathesis of olefins and in the isomerisation of olefins are disclosed. |
