On the photosensitivity of dibenzoylmethane,benzoylacetone and ethyl benzoylacetate in solution

The influence of sunlight on the keto-enol ratio of dibenzoylmethane, benzoylacetone and ethyl benzoylacetate in heptane solution was examined. It was shown that the tautomeric equilibrium is strongly displaced to the keto form. Important differences in the photosensitivity of β-diketones and β-ketoesters depending on the structural features and the nature of irradiation have been established.     

Study of Preferential Solvation in Binary Mixtures by Means of Frequency-Domain Fluorescence Spectroscopy

The preferential solvation of 8-N,N-(dimethylamino)-11H-indeno[2,1-a]pyrene, Py(S)DMA, in its transient charge transfer (CT) state in binary solvents such as toluene/DMSO liquid mixtures was studied by means of frequency-domain fluorometry. The data obtained were considered within the following kinetic scheme: the preferential solvation was described by the system of consecutive reversible reactions of which each step is associated with the absorption of one DMSO molecule in the first solvation shell of the fluoresent Py(S)DMA dipolar CT molecule. The rate constants of the first two reversible elementary processes (i.e., the decay of solvation complexes of Py(S)DMA with one and two polar molecules, k _–1 = 1.1 10⁹ s^–1 and k _–2 = 1.4 10⁹ s^–1) were determined.     

Some methodological problems of polymer science

An attempt was made to discuss some methodological problems of polymer science. An emphasis was made of the necessity to study the methodology problems.Translated from Mekhanika Polimerov, No. 2, pp. 197–202, March–April, 1970.