COORDINATION POLYMERIZATION OF OLEFINS: CATALYST STUDIES. PART I. THE INFRARED SPECTROSCOPIC INVESTIGATION OF THE SYSTEMS (CH3)3Al–TiCl4AND (CH3)2Zn–TiCl4

Abstract

An infrared spectroscopic investigation of the reaction between titanium tetrachloride and trimethyl aluminum in the vapor phase was carried out at six different reactant ratios. The study defined the course of the initial reactions; demonstrated the importance of equilibria among the products in this system as contrasted with dimethyl zinc – titanium tetrachloride; indicated the relative alkylating power of trimethyl, dimethylchloro, and methyldichloro aluminum toward titanium tetrachloride and methyl titanium trichloride; and supported the view that the active catalyst site in such systems is the titanium–carbon bond in reduced titanium alkyls. A new mode of decomposition of methyl titanium trichloride leading to active catalyst was found which can account for reported variable catalyst activities at Al/Ti ratios less than 1. Individual infrared spectra in the range 1500 to 300 cm⁻¹for trimethyl aluminum, dimethyl aluminum dichloride, methyl aluminum dichloride, methyl titanium trichloride, and dimethyl titanium dichloride as well as those of the initial reaction mixtures are presented.