Synthesis and Spectral Study of a New Family of 2,5-Diaryltriazoles Having Restricted Rotation of the 5-Aryl Substituent

Efficient synthesis of 2,5-diaryl substituted 4-azido-1,2,3-triazoles by the reaction of sodium azide with dichlorosubstituted diazadienes was demonstrated. The optical properties of the prepared azidotriazoles were studied to reveal a luminescence maximum in the 360–420 nm region. To improve the luminescence quantum yields a family of 4-azido-1,2,3-triazoles bearing ortho-propargyloxy substituents in the 5 position was prepared. Subsequent intramolecular thermal cyclization permits to construct additional triazole fragment and obtain unique benzoxazocine derivatives condensed with two triazole rings. This new family of condensed heterocycles has a flattened heterocyclic system structure to provide more conjugation of the 5-aryl fragment with the triazole core. As a result, a new type of UV/“blue light-emitting” materials with better photophysical properties was obtained.

Структура, генерационные характеристики и фотостабильность новых гетерил-кумаринов

The effect of the structure of a number of new laser media based on heteryl-coumarins on their spectral and lasing characteristics is studied under conditions of coherent nanosecond and microsecond lamp pumping. The effect of triazole, oxadiazole, and thiazole heterocycles in the structure of coumarin molecules on the spectral, lasing, and photochemical properties of their ethanol solutions has been studied. The analysis of the influence of heteroatoms, heterocyclic radicals, and an aryl fragment in the conjugation chain on the electron density distribution in the structure of coumarin molecules is carried out. It was shown, that triazole and oxadiazole heterocycles provide better lasing ability and photostability of the compounds under study, which made it possible to create new laser media generating radiation in the spectral range 490-560 nm with a sufficiently high efficiency.

Tandem intramolecular cyclisation/1,3-aryl shift in N-(4,4-diethoxybutyl)-1-arylmethanimines (Kazan reaction): synthesis of 3-benzylidene-1-pyrrolines

A novel tandem reaction, which transforms N-(4,4-diethoxybutyl)imines to 3-arylidene-1-pyrrolines via intramolecular Mannich reaction/[1,3]-sigmatropic rearrangement of the aryl fragment is described.