Crystal and molecular structure of 2-(2′-methylaminophenyl)-4H-3,1-benzoxazine-4-one

A planar structure for molecules of 2-(2-methylaminophenyl)-4H-3,1-benzoxazine-4-one was found by x-ray structural analysis. Shortening of the N-Ph bond and lengthening of the distance between amino- and azine-N atoms in comparison to the tosyl analog was demonstrated to lead to a bathochromic shift of the absorption spectrum and a hypsochromic displacement of the luminescence spectrum. As a result, the Stokes shift of 2-(2-methylaminophenyl)-4H-3,1-benzoxazine-4-one is smaller than that of 2-(2-tosylaminophenyl)-4H-3,1-benzoxazine-4-one. In the crystal, molecules of 2-(2-methylaminophenyl)-4H-3,1-benzoxazine-4-one are stacked with intermolecular interaction energy between molecules in the stack of –12.5 and –14.2 kcal/mole. The stacks are joined into layers parallel to (010).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1781–1785, August, 1989.     

Molecular and crystal structure of N,N′-di-(p-tosyl)-2,8-dimethoxyphengomazine-6,12-dione

Branch of the Institute of Chemical Physics, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 29, No. 5, pp. 109–115, September–October, 1988.     

Molecular structure of N-mesityl-6H-anthra[9,1-bc]pyrrol-6-one

The molecular and crystalline structure of 1-(2,4,6-trimethylphenyl)-6H-anthra-[9,1-bc]pyrrol-6-one was determined by the x-ray structural method. There is a larger uniformity of the bonds in the benzene ring of the isoindole fragment than in the N-substituted isoindoles; this derives from the electronic influence of the keto group. The structure of the whole molecule does not have marked 1,10-anthraquinoid character.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 485–490, April, 1988.     

Virus Particles Monitored by Fluorescence Spectroscopy: A Potential Detection Assay for Macromolecular Assembly¶

Native fluorescence spectroscopy was used for in situ investigations of two lipid‐containing bacteriophages from the cystovirus family as well as their Pseudomonad host cells. Both the viruses φ6 and φ12 and their bacterial host proteins contain the amino acid tryptophan (trp), which is the predominant fluorophore in UV. Within proteins, trp's structural environment differs, and the differences are reflected in their spectroscopic signatures. It was observed that the peak of the trp emission from both viruses was at 330 nm, a significantly shorter wavelength than trp in either the Pseudomonad host cells or the amino acid's chemical form. This allowed us to monitor the viral attachment process and subsequent lytic release of progeny virus particles by measurement of the trp emission spectra during the infection process. This work demonstrates that fluorescence may offer a novel tool to detect viruses and monitor viral infection of cells and may be part of a biodefense application.     

Electronic structures and spectral and acid-base properties of pyrrol-, thiophen-, and furananthrones

The IR spectra, electronic absorption and luminescence spectra, solvatochromism, and basicities of compounds of the 6H-dibenz[cd,g]indol-6-one, 6H-anthra[9,1-bc] thiophen-6-one, and 6H-anthra[9,1-bc]furan-6-one groups were studied. The interrelationship between the indicated properties and such structural factors as the 1,10-anthraquinoid structure, the presence of a -surplus heteroring, and the presence of substituents was examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 486–493, April, 1985.     

Reaction of Lawesson Reagent with 1,2-(<Emphasis Type="Italic">N</Emphasis>-Benzyliden)iminoalcohols

Lawesson reagent reacts with 2-(N-benzylidenamino)-1-alkanols in boiling benzene to give 2-(N-benzylidenamino)alkoxy(4′-methoxyphenyl)dithiophosphonates. The primarily formed adducts under the action of methanol eliminate benzylidene fragment to give the corresponding 2-aminoalkoxy(4′-methoxyphenyl)dithiophosphonates.     

Synthesis and conformational analysis of phosphine selenides

Methods of preparation of complex phosphine selenide via the original Trofimov–Gusarova reaction are described. The results of the products conformational analysis by means of a set of physical methods (IR spectroscopy, dipole moments, and quantum chemical calculation) are presented.