Preparation of schiff base derived from 3,4-dimethoxybenzaldehyde and p -aminobenzoic acid by supersonic speed gas impacting method

A schiff base derived from 3,4-dimethoxybenzaldehyde and p-aminobenzoic acid (sbda) was synthesized by novel supersonic speed gas impacting method. the morphology and geometric structure of the synthesized schiff base sbda were investigated,the results showed that the particles of sbda were not completely regular and the homo and lumo of sbda optimized geometry structure using the semiempirical method pm3 were -9.115 ev and -1.191 ev,respectively,and some bond length of synthesized sbda became short and bone angle became large compared to the reactant. the thermogravimetric analysis results indicated that sbda began to decompose above 280°c; the decomposition temperature and thermogravimetric rate could vary with the different heating rate. © 2014 yan-hua cai and wen luo.