Functional derivatives of thiophene

2-Aryl-4-oxothieno[2,3-d]oxazine derivatives were synthesized. Opening of the oxazine ring to give 2-benzamidothiophene-3-carboxylic acid hydrazide derivatives is observed when these compounds are treated with hydrazine hydrate.See [1] for Communication 17.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 45–46, January, 1980.     

Functional derivatives of thiophene. 17. Synthesis of thienylhydrazine derivatives

Substituted thienylhydrazones of aromatic aldehydes and cyclohexanone were obtained. It is shown that the sodium salts of the latter are readily acylated and alkylated. The hydrolysis of carbethoxythienylmethylhydrazones of benzaldehyde in alkaline media is accompanied by decarboxylation.See [1] for Communication 16.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 607–608, May, 1979.     

Ammonia-sensing properties of acridine immobilized in SiO2 sol-gel films

The spectral and luminescent properties of acridine in SiO₂ films synthesized by the sol-gel method using acid hydrolysis of tetraethoxysilane are studied. It is shown that acridine in films exists in protonated form. Ammonia-gas-sensing properties of films doped with acridine are studied by the fluorescence response (decrease in the intensity) of the protonated form. The possibility of multiple use of a sample without a noticeable decrease in its sensitivity is demonstrated. It is shown that the fluorescence response to a maximal permissible concentration of ammonia in the gas mixture with argon is 6–8%.     

Photo- and electroluminescence of mixed-ligand Eu(III) complexes

Spectral and luminescent properties of mixed-ligand Eu(III) complexes were studied in solutions and in polyvinylcarbazole (PVC) thin films. Trends in their variations were found depending on the complex structure and excitation mode. The electroluminescence was observed in ITO/PEDOT/Eu complex:PVC/CaMg/Al devices. Their current-voltage and voltage-brightness characteristics were investigated.     

Photo- and electroluminescence of Eu(III) and Tb(III) coordination compounds in thin polyvinylcarbazole films

Organic thin-film structures based on Eu(III), Tb(III), and polyvinylcarbazole coordination compounds are synthesized. Their photo- and electroluminescent properties and volt-ampere and volt-brightness characteristics are investigated.     

Synthesis of 4H-[1]benzopyrano[3,4-c][1,2,5]thyadiazol-4-one and its reactions with some nucleophilic and electrophilic agents

The reaction of 3,4-diaminocoumarin with thionyl chloride gave 4H-[1]benzopyrano[3,4-c][1,2,5]thiadiazol-4-one (II), which was cleaved by the action of nucleophilic agents to the corresponding 4-(2-hydroxyphenyl)-1,2,5-thiadiazole-3-carboxylic acid derivatives. The nitration of II leads to the 8-nitro or 6,8-dinitro derivative; the latter was isolated in the form of 4-(2-hydroxy-3,5-dinitrophenyl)-1,2,5-thiadiazole-3-carboxylic acid.See [3] for our preliminary communication.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 977–981, July, 1988.     

Spectral‐Luminescence and Generation Properties of 1‐Aza‐2‐Methyl‐6‐Aminopyrene and of Its Protolytic Forms

Spectral manifestations of protolytic forms of 1aza2methyl6aminopyrene in ethanol and aqueous solutions are investigated. The ionization constants of the protolytic forms are determined. The generation properties and photostability of a neutral molecule and a cation in excitation by an excimer XeCl laser are studied.