Synthesis of magnesium dicyclopentadienide catalyzed by titanium and vanadium derivatives

Synthesis of magnesium dicyclopentadienide from metal and cyclopentadiene i n THF is effectively catalyzed by the derivatives of vanadium and titanium, The kinetics of the synthesis, as well as thermodynamic parameters of reag ents adsorption on the magnesium surface, have been determined. The process catalyzed by titanium derivatives is accompanied by the quantitative hydro genation of cyclopentadiene to cyclopentene whereas the catalysis by vanadi um derivatives leads to hydrogen gas evolution. A number of reaction interm ediates including Cp2TiCl, Cp2TiH2MgCl, Cp2Ti(cyclo-C5H7) and Cp2V, were id entified by the electron spin resonance method. The equilibrium constants, enthalpies and entropies of adsorption of metal halides on the magnesium su rface were calculated. Copyright (C) 2001 John Wiley & Sons, Ltd.