Investigation of h complexes of 2-thienyl phenyl ketones by IR spectroscopy

The shifts of the stretching vibrations of the hydroxyl groups of phenol and pentachlorophenol during the formation of intermolecular hydrogen bonds with 2-thienyl phenyl ketones containing substituents in the benzene ring were measured. A correlation dependence between theD _OH values and ⁺ substituent constants was established.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 482–485, April, 1974.     

Dipole moments of thiophene analogs of chalcones and their vinylogs

The dipole moments of 25α, β unsaturated ketones of the thiophene series are measured in benzene at 25°, and their most probable coplanar conformations established. For the systems studied it is shown that, in the static state, the 2-thienyl group exhibits an electron-donating effect, greater than those of 2-furyl and phenyl. Introduction of electron-donating and electron-accepting substituents into the molecule of 1-(thienyl-2)-3-phenylpropenones as well as shift of the carbonyl group away from the aryl one towards the heterocyclic ring, leads in general to an increase in dipole moment. A linear relationship is found for the changes in dipole moment of isomeric thiophene ketones due to electron-donating substituents. Dipole moments of propen-3-ones correlate satisfactorily with Hammett σ parameters for substituents, and intermolecular distances.     

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.     

Dipole moments of selenophene analogs of the chalcones

The dipole moments of 24 selenophene analogs of the chalcones have been measured and have been compared with the data calculated by a vectorial additive scheme and also with their chemical structures. Considerations are expressed on the conformational state of the molecules of the compounds investigated. The existence of a correlation between the dipole moments the intramolecular distances, and the Hammett's -parameters has been shown. The applicability of Higashi's equation to the calculation of for , -unsaturated ketones is pointed out.     

Polarographic examination of 5-aryl-2-(2-thienyl)-oxazoles and -1,3,4-oxadiazoles

The polarographic behavior of 5-aryl-2-(2-thienyl)oxazoles and -1,3,4-oxadiazoles has been studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1550–1552, November, 1986.     

Electronic spectra of α,β-unsaturated ketones — Indole derivatives

The electronic spectra of (3-indolyl)-, (1-methyl-3-indolyl)-, and (6-nitro-3-indolyl)-substituted ,-unsaturated ketones were measured and interpreted. 3-Indolyl and N-methyl-3-indolyl substituents have a considerable bathochromic effect as compared with the phenyl group in the investigated systems as a consequence of the electron-donor effect, which surpasses that for 4-anisyl, 2,4-dimethoxyphenyl, 2-furyl, 2-thienyl, and 2-selenienyl and differs only slightly from 2-pyrrolyl. The introduction of electron-donor substituents into the p position of the benzene ring of 1-(3-indolyl)-3-phenyl-1-propenone causes a red shift of the long-wave absorption band, the difference in frequencies of which correlates with the Hammett substituent constants. Except for compounds containing a nitro group,1-(3-indolyl)-3-aryl-3-propenones and their N-methyl derivatives fluoresce well in alcohol with _max >475 nm.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 949–953, July, 1972.     

Electronic absorption spectra of the cations and anions formed from pyrrole analogs of the chalcones

The electronic absorption spectra of 29 pyrrole analogs of the chalcones have been studied in solutions of strong acids and alkalies, in which the corresponding cations and anions are formed. It has been shown by means of the IR spectra that the protonation of the pyrrole chalcones takes place at the carbonyl group. Considerations are given of the structure of the organic cations and anions studied and of the characteristic features in the change in their coloration as a function of their chemical structure. Satisfactory correlations have been found between the shift of the absorption frequency of the long-wave band which takes place at the transition from a neutral solution (molecules) to an acid solution (cations) or to an alkaline solution (anions) and Hammett's o constants. Three 3-(4-halophenyl)-1-(2-pyrryl)propenones not previously reported in the literature have been synthesized.