Molecular Switching and PET Effect in the Molecules of 2-(9-Anthrylmethylaminomethylene)benzo[b]thiophene and Its N-Acetyl Derivative

Russian Journal of Organic Chemistry -     

Mixed dynamic problem for a half plane and its application to rock mechanics

The mixed dynamic problem of the theory of elasticity is solved for an isotropic half plane. The dynamic equations are reduced to integration of fourth-degree equations in partial derivatives with constant coefficients, after whose solution, the components of the stress tensor and displacement vector are written in a form similar to that introduced by Lekhnitskii for an anisotropic body. The stress state of a rock mass subjected to rapid face advance in a seam is investigated using the solution obtained. The stress distribution is analyzed numerically. The existence of a critical rate at which the stress increases without restriction is demonstrated.Donetsk. Translated from Teoreticheskaya i Prikladnaya Mekhanika, No. 21, pp. 56–61, 1990.     

Benzenoid-quinoid tautomerism of azomethines and their structural analogs. 42. Synthesis,structures, and spectral-luminescence properties of 3-hydroxy-2-acetylbenzo[b]thiophene imines

N-Aryl- and N-alkylimines of 3-hydroxy-2-acetylbenzo[b]-thiophene, the most stable isomeric form of which, according to the UV, IR, and ¹H NMR spectra data, is the E-keto enamine structure, were synthesized. Irradiation of the aminovinyl ketones in the region of the long-wave absorption band causes thermally and photochemically reversible EZ isomerization. 2-Aminoethylidene-3-(2H)-benzo[b]thiophenones have low-intensity fluorescence with a normal Stokesian shift, which is absent in solutions of their lithium and sodium salts.See [1] for Communication 41.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 591–595, May, 1989.     

2-[N-Acetyl-N-(2-fluorenonyl)aminomethylene]benzo[b]- thiophen-3(2H)-one,a Molecular Fluorescent Switch

Russian Journal of Organic Chemistry -     

Synthesis and photochromic and fluorescence properties of 3-(1-benzyl-5-methoxy-2-methylindolyl)-4-thienyl-substituted furan(pyrrole)-2,5-diones

New nonsymmetrical dihetarylethenes, 3-(1-benzyl-5-methoxy-2-methyl-1H-indol-3-yl)-4-(3-thienyl)furan-2,5-dione and 1-alkyl- and (1-aryl)-3-(1-benzyl-5-methoxy-2-methyl-1H-indol-3-yl)-4-(3-thienyl)-1H-pyrrole-2,5-dione, exhibiting photochromic properties in solutions were synthesized. Noncyclic isomers of dihetarylethenes show fluorescence with quantum yields up to 0.13.     

Synthesis, structures, and photochromic properties of N-aryl-3-indolylfulgides

New 3-indolylfulgides, viz., 3-[1-(1-aryl-5-methoxy-2-methyl-1H-indol-3-yl)ethylidene]-4-(1-methylethylidene)tetrahydro-2,5-furandiones, were synthesized. These compounds were obtained as E-isomers, as demonstrated by X-ray diffraction, electronic spectroscopy, and ¹H NMR spectroscopy. Fulgides exhibit photochromic properties in solution. The cyclic dihydrocarbazole photoisomers of indolylfulgides show fluorescence properties and are characterized by high thermal stability. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1417–1423, July, 2008.     

Benzoid-quinoid tautomerism of azomethines and their structural analogs: LIV. Dibenzo(benzo)-18-crown-6-containing Imines of 5-hydroxy-2,3-tetramethylene- and 5-Hydroxy-2,3-diphenylbenzo[<Emphasis Type="Italic">b</Emphasis>]furan-4-carbaldehydes

Dibenzo(benzo)-18-crown-6-containing N-arylimines of 5-hydroxy-2,3-tetramethylene- and 5-hydroxy-2,3-diphenylbenzo[b]-furan-4-carbaldehydes were synthesized and their spectral luminescence properties were investigated. In solutions of 6-bromo- and 6-nitro-substituted compounds a tautomeric equilibrium exists between the benzoid and quinoid forms. In the course of complexing of crown-ether-imines of 5-hydroxy-6-nitro-2,3-diphenylbenzo[b]furan-4-carbaldehyde and 5-hydroxy-6-nitro-2,3-tetramethylenebenzo[b]furan-4-carbaldehyde with cations of alkali and alkaline earth metals the content of the quinoid form was found to decrease. This phenomenon was accompanied by essential changes in the absorption and fluorescence spectra characteristic of chemosensor systems with an intramolecular charge transfer (ICT).     

Chemosensors based on <Emphasis Type="Italic">N</Emphasis>-(2-aminophenyl)-<Emphasis Type="Italic">N</Emphasis>-(9-anthrylmethyl)amine: II

A series of N-(9-anthrylmethyl)arylimines was prepared by condensation of N-(2-aminophenyl)-N-(9-anthrylmethyl)amine with aromatic aldehydes. The study of the luminescent and complexing properties of compounds obtained showed that 2-{[2-(9-anthrylmethylamino)phenylimino]methyl}-1-naphthol and 1-{[2-(9- anthrylmethylamino)phenylimino]methyl}-6-bromo-2-naphthol were efficient highly selective chemosensors of cations Hg²⁺.