Synthesis and spectrophotometric study of some amino derivatives of thiophene analogs of chalcone

Eight amino derivatives of thiophene analogs of chalcone were obtained by reduction of the corresponding nitro derivatives with stannous chloride in concentrated hydrochloric acid, and their UV absorption spectra in dioxane were measured. The long-wave band was assigned to the corresponding fragments of the molecule on the basis of a comparison of the absorption curves of the investigated compounds with the curves of simpler compounds — aminoacetophenone, aminobenzalacetone, acetothienone, etc.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 198–203, February, 1977.     

1,3,5-Triaryl-Δ2-pyrazolines with a nitro or amino group in the N-phenyl ring

A number of p-nitrophenylhydrazones of chalcones and 1-(p-nitrophenyl)- and 1-(p-aminophenyl)-3-aryl-5-phenyl-2-pyrazolines were synthesized, and their UV and IR spectra were measured. It is shown that the direction of polarization in the system of the ground and first excited states of the pyrazolines depends substantially on the character and position of the substituents introduced; the experimental data are compared with the results of calculation of the electronic states of the molecules by the Pariser-Parr-Pople (PPP) method. It was established that the nitro compounds have luminescence properties and that their absorption spectra in inert solvents have a vibrational structure.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1538–1543, November, 1977.