PM3 method has been used to study the reaction mechanism of a newly synthes
ized squarylium derivative,2- (N, N - dihydroxyethyl)amino - 4 - dimethyami
nophenyl squarylium and to optimize the structures of reactant, products an
d transition states. Calculation results have shown that the reaction with
(N, N - dihydroxyethyl)amino, dimethyaminophenyl and squary produces ortho
- product and para - product,and that para - product is easier to form.