Photophysical and Photocatalytic Parameters of Sulfo and Tetrabromosulfo Derivatives of Fluorescein

Acid-base, absorption, and luminescence properties of Fluorescein and Eosin analogs containing a sulfo group have been examined. Using the flash photolysis technique, triplet-triplet absorption and formation of radical anions and radical cations have been detected. The dyes under study form hydrophobic complexes with cationic surfactants at a ratio of 1 : 2. Photocatalytic activity of the dyes in generation of hydrogen from water has also been studied.     

Photochemistry of quaternary salts of aromatic heterocycles and some of their mesoionic derivatives (Review)

The photochemical methods far the synthesis of quaternary salts of aromatic heterocycles, their photochemical reduction reactions, photoreactions with water, some photochemical transformations that proceed without a change in the charged heterocycle, and photoreactions involving valence isomerization and fragmentation of the mesoionic derivatives are examined.     

Investigation of the reaction of 1-methyl-2,5-dichloro-3,4-diformylpyrrole with amines

The reaction of 1-methyl-2,5-dichloro-3,4-diformylpyrrole with amines of the aliphatic series leads to products of replacement of one chlorine atom. With aromatic amines the reaction takes place at one of the formyl groups to give aminals. The latter in the presence of excess amine readily give bisazomethines of 1-methyl-2-chloro-5-arylamino-3, 4-diformylpyrrole, which can also be obtained directly by the reaction of dichlorodiformylpyrrole with arylamines. It is shown that in this case one of the formyl groups and the adjacent chlorine atom react initially, after which the second formyl group reacts. The chlorine atom in bisazomethines of 1-methyl-2-chloro-5-arylamino-3,4-diformylpyrrole has high nucleophilic lability and is easily replaced by a hydroxy group or a piperidine residue.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1489–1493, November, 1981.     

Synthesis,photophysical and electrochemical properties of novel 6,12-di(thiophen-2-yl) substituted indolo[3,2-b]carbazoles

Novel 5,11-dialkyl-6,12-di(thiophen-2-yl) substituted 5,11-dihydroindolo[3,2-b]carbazoles have been obtained and plausible ways for their further modifications via the Friedel–Crafts reaction are presented. The formylation of these indolo[3,2-b]carbazoles with dichloromethyl alkyl esters catalysed by Lewis acids leads to the formation of the corresponding 2,8-diformyl derivatives. Applicability of this formylation method for modification of indolo[3,2-b]carbazoles bearing electron-rich aromatic substituents at C-6 and C-12 has also been demonstrated. The Knoevenagel condensation of 2,8-dialdehydes with active methylene nitriles has been studied. The measurements of optical and redox properties for a number of new indolo[3,2-b]carbazoles have been performed.     

Synthesis of 2-arylbenzoxazoles from copper complexes of o-nitrosophenols and aromatic aldehydes

2-Arylbenzoxazoles were obtained by heating copper complexes of o-nitrosophenols with aromatic aldehydes in tetralin.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1338–1339, October, 1976.