Thermochemistry of metal alkoxides. Part 2.—Heats of formation of some titanium alkoxides

Abstract

Measurements of the heats of alcoholysis of titanium tetraethoxide in cyclohexane have been used to determine the standard heats of formation of various titanium tetra-alkoxides ΔH^°_f[Ti(OR)₄, liq.], where R= n-C₃H₇, isoC₃H₇, n-C₄H₉, sec.-C₄H₉, n-C₅H₁₁ and tert.-C₅H₁₁. The values for Ti(OC₄H₉-n)₄ and Ti(OC₅H₁₁-tert.)₄ were checked by measurements of heats of reaction of the alcohols with titanium tetradiethylamide. The data were used to derive values for ΔH^°_f[Ti(OR)₄, g], D(Ti—O) the average bond dissociation energy and E(Ti—O) the bond energy terms for Ti—O bonds. From the value of ΔH^°_f{Ti[N(C₂H₅)₂]₄, liq.}=–100 kcal/mole it was calculated that D(Ti—N)∼73 kcal/mole.