Photochemically bifunctional compound from the class of spironaphthooxazines

Russian Chemical Bulletin -     

Oligosaccharide sequencing by means of mass spectrometry—I: N-phenylosotriazole acetates

Fragmentation of the acetates of the N-phenylosotriazoles of some mono-, di, tri-, tetra- and pentasaccharides under electron-impact (EI) has been studied. The mass spectra of these derivatives can be used for determination of the sequence of monosaccharide units in oligosaccharides (oligosaccharide sequencing), of molecular weight, of the location of the position of the interglycosidic bond in disaccharides and of the position of the methyl group in partially methylated monosaccharides.     

Synthesis of new spirobenzopyrans with two long-chain substituents

Two new photochromic compounds each containing two substituents with long alkyl chains in different parts of a molecule were synthesized by a sequence of direct reduction, acylation, and nitration reactions of substituted spirobenzopyrans. The structures of the compounds synthesized were determined using the ¹H NMR spectra. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2530–2533, November, 2005.     

Bromination of photochromic spironaphthoxazines

Direct bromination of photochromic compounds of the spironaphthoxazine and spironaphthopyran series was performed using N-bromosuccinimide to obtain both photochromic bromine-substituted spiro compounds and nonphotochromic 2-(naphtho[1,2-d]oxazol-2-yl)-3H-indolium bromides. The structures of the resulting products were established by NMR spectroscopy and mass spectrometry. The mechanism of bromination taking into account the involvement of both closed and open (colored) forms of spiro compounds was proposed.     

Synthesis and properties of a novel photochromic luminophore

A photochemically bifunctional compound was obtained. Its molecule includes the spironaphthoxazine and dansylamino fragments. This compound exhibits both photochromic and luminescent properties. Its spectroscopic characteristics were studied in different solvents. The electronic systems of two constituent fragments do not interact with each other. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2802–2805, December, 2005.     

Merocyanine form of photochromic spirooxazines in acid solutions

Electronic absorption and NMR spectra of solutions of photochromic spironaphthoxazines (SNOs) were studied. The addition of an acid results in the formation of a salt of the colored form of SNO. For SNOs with nitrogen-containing electron-releasing substituents, the structure of the product that formed depends on the acid concentration being the salt of the mono- or dication.