Thermochemistry of metal alkoxides. Part 1.—Heat of formation of titanium tetraethoxide

Abstract

By measuring the heats of reaction in cyclohexane of (i) titanium tetrachloride with ethanol, and (ii) titanium tetraethoxide with hydrogen chloride, the standard heat of formation of trimeric liquid titanium tetraethoxide ΔH^°_f[Ti(OC₂H₅)₄, liq.]=–349±1.4 kcal/mole has been determined. This value was confirmed by measuring the heats of similar reactions in aqueous hydrochloric acid. The value obtained by measuring heats of reaction of acetylchloride with titanium tetraethoxide and of titanium tetrachloride with ethylacetate was not in good agreement. Estimates were made of the standard heat of formation of monomeric gaseous Ti(OC₂H₅)₄(–325±2.4 kcal/mole) and the average bond dissociation energy D(101±2.1 kcal/mole) for the Ti—O bonds in this compound.