Mechanistic studies towards the reversible equilibrium between metal organic triple decker and sandwich complexes [bis{(eta(5)-Cp-R)Co}-mu-{eta(4):eta(4)-arene}] and [(eta(5)-Cp-R)Co(eta(6)-arene)] [German]

摘要

The arene ligand exchange mechanism of slipped arene triple deckers [Bis{(eta(5)-Cp-R)Co}-mu-{eta(4):eta(4)-arene}] (R = Me-5, 1,2,4 tri-tert butyl, arene = benzene, toluene) 1 was studied by H-1-NMR spectroscopy for different concentrations and solvents. It has been found that triple deckers of type 1 decompose slowly in solution. A unique equilibrium, between these triple deckers and the mixed sandwich complexes [(eta(6)-arene)Co(eta(5)-Cp-R)] and 14 e [(eta(5)-Cp)Co](solv) fragments generated in situ by decomposition of 1 exists. In addition to this equilibrium arene lability of the thus formed mixed sandwich complex type has been detected by NMR making slipped triple deckers 1 ideal single source compounds for the generation of two [(eta(5)-Cp)Co] fragments in one reaction step. Such fragments are valuable metal ligand components with high synthetic utility in organometallic chemistry. [References: 20]