Yu. P. Strokach

Synthesis and properties of dihetaryl-substituted furanones. Synthesis of photochromic dithienylethenes containing a furanone bridging fragment

The reaction of 2,5-dimethylthiophen-3-ylacetic acid with 2,5-dimethylthiophen-3-ylacetyl chloride gave 3,4-bis(2,5-dimethylthiophen-3-yl)furan-2(5H)-one which was converted into a series of 5-methylidene and 5-arylmethylidene derivatives.

Photochromism of Thienyl-Containing Dihetarylethenes with Five-Membered Cyclic Bridges

ABSTRACT Spectral-kinetic characteristics of a number of new photochromic dihetaryethenes with different five–membered cyclic bridges are measured and discussed. It was shown that these characteristics depend on a bridge structure as well as a nature of substituents in the thienyl fragments.

A comparative study of the spectral and kinetic properties of photochromic dihetarylethenes based on maleic anhydride and maleimide

A comparative spectral-kinetic study of the photochromism of a number of new thermally irreversible 1,2-diarylethenes, considered as possible candidates for 3D optical data storage, is performed. The diarylethenes studied contain as bridges either maleic anhydride or maleimide derivatives. A relation between the structure of the bridges and substituents of these compounds and their photochromic properties is established.

Crown-containing spirooxazines and spiropyrans: 1. Synthesis and the anion-"capped" complexes of photochromic aza-15-crown-5 ethers with flexible spacers

Methods for the synthesis of new spironaphthooxazines containing an aza-15-crown-5 fragment in two different positions (5′ and 9′) were developed. The spectral and photochemical properties of these compounds suggest that two competitive complexation processes occur with alkaline-earth or rare-earth metal cations differing in efficiency and selectivity. A metal cation occupies the optimum position in the crown-ether cavity with respect to the donor oxygen atom of the merocyanine form of the dye and thus can affect more strongly its spectral and photochemical properties than in the case of intermolecular interaction.

Synthesis and structure of indoline spiropyrans of the coumarin series

New indoline spiropyrans of the coumarin series were synthesized by the condensation of indoline and hydroxyformylcoumarin derivatives. Spiropyrans, viz., derivatives of 8-formyl-7-hydroxy-4-methylcoumarin and 5-formyl-6-hydroxy-4-methylcoumarin, under irradiation are transformed into open forms, which are recyclized in the dark. The compounds formed by the condensation of the indoline derivatives with 3-formyl-4-hydroxycoumarin have an open structure of the merocyanine dyes and are transformed into spiro forms neither in the dark nor under irradiation with the visible light.

Synthesis of spiropyran analogues of retinal and study of their interaction with bacterioopsin from Halobacterium salinarum

The synthesis of a series of retinal analogues containing the spiropyran moiety instead of trimethylcyclohexene ring was proposed. The interaction of the resulting retinal analogues with bacterioopsin from apomembranes of Halobacterium salinarum and the spectral characteristics of the new pigments were studied.

New bistable organic photochromic compounds for bitwise working optical memory

The results of our spectral and kinetic studies for some photochromic compounds (58 diarylethenes and 9 fulgimides) are presented. Aiming at targeted synthesis of new photochromic compounds, the structure-photochromic behavior relationship (SPBR) for the synthesized compounds has been analyzed. The perspectives for application of these compounds in development of recording media for use in optical memory devices are outlined.

Photochromic and Cation-Binding Properties of New Crowned Spiropyrans

ABSTRACT Spectral properties of new crowned spiropyrans and their cationic complexes are described.

A comparative study of the spectral and kinetic properties of photochromic derivatives of perfluorocyclopentene diarylethenes

A comparative spectral-kinetic study of the photochromism of a series of synthesized thienyl derivatives of perfluorocyclopentene dihetarylethenes is performed. A relation between the photochromic properties of these compounds (the absorption spectra of the initial and photoinduced forms, the photosensitivity, the interconversion constants of both forms, and the photodegradation) and their structure is established. For some compounds experiencing reversible and irreversible phototransformations, photoinduced fluorescence was observed. The data obtained give grounds to suggest that the compounds synthesized can be used in developing recording media for two-photon 3D main and archival storage.

Crown-containing spironaphthoxazines and spiropyrans. 2. Influence of metal cations on the photochromic properties of spironaphthoxazines linked with aza-15(18)-crown-5(6) ethers

Spironaphthoxazines linked with aza-15(18)-crown-5(6) fragments were synthesized and studied for the first time. Addition of alkaline-earth cations to solutions of crown-containing spironaphthoxazines causes a hypsochromic shift of the absorption band of the spiro form and a bathochromic shift of the absorption band of the merocyanine form, shifts the equilibrium to the merocyanine form, and changes the lifetime of the photoexcited merocyanine form. The spectral and kinetic data were used to propose a mechanism of complexation and calculate the stability constants of the resulting complexes. The complexation involves the crown fragment and the merocyanine oxygen atom. The type of the complex is determined by the cation nature and size.