Measurement of surface absorption in optical materials by the method of laser photothermal radiometry

The present work is devoted to the development of the method of laser photothermal radiometry with a view to increasing its spatial resolution over the depth of the specimen when surface layers of the substance of thickness about 1 μm or less are to be investigated. As an example, results of an investigation of radiation absorption in the surface layer of a lithium niobate crystal are presented. The absorption index measured at a wavelength of 1.08 μm was ∼0.6 cm⁻¹. “Polyus” Research Institute, 3, Vernadskii Ave., Moscow, 117342, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 82–84, January–February, 1997.     

1-Azabicyclic compounds. 24. Selectivity of position of nitration of 1,2-dihydropyrrolizine, 5,6,7,8-tetrahydropyrrocoline and pyrrole homologs

The selectivity of the position of nitration of 1-methylpyrrole, 1,2-dimethylpyrrole, 1,2-dihydropyrrolizine, and 5,6,7,8-tetrahydropyrrocoline was found. In contrast to the selectivity of substitution during nitration of their carbocyclic analogs, o-xylene, indane and tetraline, the fraction of the -nitro-isomer in the nitration products of 1,2-dimethylpyrrole is smaller than the fraction of -nitro derivatives of 1,2-dihydropyrrolizine and 5,6,7,8-tetrahydropyrrocoline, and in the two latter cases the isomers are almost equally distributed. During nitration of the above bicyclic pyrroles, the Mills-Nixon effect does not appreciably influence the selectivity of the position of the reaction.See [1] for Communication 23.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1489–1491, November, 1987.     

Carbazoles Stannylation

Stannylation of 3,6-dibromocarbazoles with lithium trimethylstannanide in THF was investigated. At treating 3,6-dibromo-9-alkylcarbazoles with lithium trimethylstannanide arise 3,6-bis(trimethylstannyl)-9-alkylcarbazoles. The 3,6-dibromocarbazole unsubstituted at nitrogen affords lithium 3,6-bis(trimethylstannyl)-carbazol-9-yl. The conditions of its generation, alkylation, and conversion into 3,6-bis(trimethylstannyl)carbazole are considered.     

A generalization of the denjoy integral

We prove that the IsekiM-integral is substantially more general than the Denjoy integral. Translated fromMatematicheskie Zametki, Vol. 62, No. 5, pp. 766–772, November, 1997. Translated by I. P. Zvyagin     

Synthesis and x-ray structural analysis of 2-amino-4-cyanomethylene-5,5-dimethylthiazoline

The reaction of thiourea with 4-hydroxy-4-methyl-2-pentynenitrile in triethylamine is accompanied by heterocyclization and the formation of 2-amino-4-cyano-methylene-5, 5-dimethylthiazoline, whose structure was established by x-ray structural analysis (XSA).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2344–2346, October, 1989.     

Simplified calculation of pressure shift and broadening of molecular lines

Gor'kii State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 33, No. 12, pp. 1349–1356, December, 1990