Thermochemistry of metal alkoxides. Part 3.—Heats of formation of vanadium tetratertiarybutoxide and chromium tetratertiarybutoxide

Abstract

The standard heats of formation of vanadium and chromium tetratert.-butoxides have been determined by means of reaction calorimetry. Values for ΔH^°_f[M(OC₄H₉-tert.)₄, g] were derived: Ti, –395; V, –328; Cr, –305 kcal/mole, and discussed in terms of average bond dissociation energies D(M—O) and bond energy terms E(M—O). The order of decreasing bond strengths Ti—O>V—O>Cr—O was discussed in terms of the increasing electronegativity of the metal ^xTi< ^xV(IV)< ^xCr(IV). The strengths of Ti—F, Ti—O and Ti—N bonds were compared and discussed in terms of electronegativities.