The synthesis and structural characterization of mono- and tris-boryloxide
complexes of aluminum are described. The mono-boryloxide aluminum species a
re found to catalyze the conversion of borinic acids to cyclic boroxines (R
BO)(3) with elimination of mesitylene (DeltaH(double dagger) 89.1 kJ mol(-1
.), DeltaS(double dagger) 145 J mol(-1) K; DeltaG(double dagger) (293 K) 46
.7 kJ mol(-1)).