CATALYZED CYCLOTRIMERIZATION OF ACETYLENE - A COMPUTATIONAL STUDY

Ab initio local density functional computations of electronic structur e are used to investigate the mechanism of the cyclotrimerisation of a cetylene catalysed by extraframework ions of nickel in zeolite-Y. Crit eria based on the optimisation of orbital overlap allow us to arrive a t the most favourable orientation of the reactants for the reaction to ensue. Key intermediates in the possible reaction pathway are identif ied and detailed information is derived on the nature of the bonding b etween acetylene and Ni2+ and the way it changes during the course of the trimerisation.