The ROMP catalysts Mo(CO)(5)PPh3/alkylaluminum with unstrained cyclic and linear dienes as initiators of the addition polymerisation
(EN)
Bokaris, E. P.
(EN)
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
(EL)
Bokaris, E. P.
(EN)
We study the polymerisation of a series of unstrained cyclic and acyclic dienes with the catalytic system of Mo(CO)(5)PPh3/alkylaluminum. The Mo(CO)(5)PPh3/alkylaluminum catalyse the nonmetathesis polymerisation, through a pair of ionic complexes similar to that of Ziegler-Natta mechanism, and not through the ROMP (Ring-Opening-Metathesis-Polymerisation) mechanism followed by strained olefins. Because of the nature of these complexes the reactivity is lower with respect to that of a common Ziegler-Natta catalyst, such as Cp2TiCl2/Et3Al2Cl3, as it is demonstrated, by means of kinetics and ESR measurements, in the case of the polymerisation of of 1,5-cyclooctadiene. Similarly to the Ziegler-Natta catalysts, they give cyclised products in the polymerisation of 1,5-hexadiene and 1,7-octadiene, and the 1,4-cis unit in the case of the polypentadienes. Finally we find that they are active catalysts for the polymerisation of styrene.
(EN)
