A STUDY OF SOME S-TRIAZIN-DELTA(2)-PYRAZOLINE DERIVATIVES BY DERIVATIVE ABSORPTION AND EMISSION SPECTROPHOTOMETRY - I - THE MODEL OF THE EXCITED-STATE OF 1,3-DIARYL-DELTA(2)-PYRAZOLINES

Fifteen 1,3-diaryl-Delta(2)-pyrazolinic derivatives, whose arylic nucl ei are of the benzenic type, as well as sixty-nine derivatives whose a rylic nucleus grafted to N-1 nitrogen atom of Delta(2)-pyrazolinic cyc le is of s-triazinic type were synthesized and studied A new structura l model of the molecule in excited state valid for a large series of p yrazolinic derivatives is advanced; it is based on the values of net:c harges, the variation of electron density and the interpretation of th e effects of substituents grafted on Delta(2)-pyrazolinic ring upon th e electronic spectra.