AMMOXIDATION OF METHYLAROMATICS OVER VANADIUM PHOSPHATE CATALYSTS .1.EFFECT OF THE SIZE, POSITION AND ELECTRONIC-PROPERTIES OF SUBSTITUENTS ON THE CATALYTIC CONVERSION OF METHYLAROMATICS TO THE CORRESPONDING NITRILES

The heterogeneous-catalytic ammoxidation of several mono- and disubsti tuted methylaromatics and heteroaromatics to their corresponding nitri les was studied. The reaction was carried out on an ammonium oxovanadi um pyrophosphate ((NH4)(2)[(VO)(3)(P2O7)(2)]) generated during the cat alytic process. The study shows that the catalytic activity and the ni trile selectivity depend mainly on the position and the electronic nat ure of the particular substituent due to a changed accessibility of th e methyl group as well as a possible different electronic stabilizatio n.