Study of the reactions between titanium tetrachloride and ethylaluminium compounds in hydrocarbon solution: I. Formation and properties of brown precipitates

Abstract

Abstract The reaction between TiCl 4 and AlEt 3 , AlEt 2 Cl and AlEtCl 2 at 80°C in isooctane was investigated for those Al/Ti ratios at which brown precipitates are formed. In these reactions Ti(IV) is not reduced beyond Ti(III). The extent of reduction was determined by oxidimetry and colorimetry; the two methods gave concordant results. Among the gaseous reaction products ethyl chloride was determined quantitatively by gas chromatography. Its formation is ascribed to a secondary reaction: The C 2 H 5 radicals are formed in the main reaction in which the ethyl‐aluminium chlorides are converted into AlCl 3 and the triethylaluminium into Al 2 EtCl 5 . By means of the conversions indicated above the relation between the percentage of reduction of Ti(IV) to Ti(III) and the Al/Ti ratio is accounted for quantitatively. The precipitates formed in the system AlEt 3 /TiCl 4 were found to consist mainly of the brown modification of TiCl 3 in which about one sixth of the titanium is replaced by aluminium.