4-Diphenylphosphinosydnone imines as bidentate ligands

The synthesis and characterization of new 3-substituted-4-diphenylphosphinosydnone imines (1,2,3-oxadiazolium-imines-5) are reported.     

Interatomic interactions in the crystal of (C4H11N2)2(C4H12N2)[Mo(CN)8]: comparison of two approaches

Two approaches to the crystal packing analysis, namely the topological analysis of the electron density distribution function in terms of the quantum theory Atoms in Molecules and the stereoatomic model, were compared as applied to the crystal structure of (C₄H₁₁N₂)₂(C₄H₁₂N₂)[Mo(CN)₈]. The data obtained by analyzing the quasi-static electron density distribution function provide an estimate of the scope of applicability and the accuracy of the stereoatomic model for the evaluation of the volume of the complex-forming atom and the determination of a system of intermolecular interactions.     

4,4′-Bis(nitramino)azofurazan and its salts. Study of molecular and crystal structure based on X-ray and quantum chemical data

4,4′-Bis(nitramino)azofurazan 2 was obtained by nitration of 4,4-diaminoazofurazan 1. Molecular and crystal structure of nitramine 2 and its ammonium salt 3 were studied by X-ray method and quantum chemical calculations at M052X/aug-cc-pvdz level of theory. Both compounds adopt ap-ap-ap conformation. It was shown that the structure of furazan cycle significantly depends on the nature of the substituents at carbon atoms. Crystal structures of 2 and 3 are characterized by sufficiently high density (1.996 and 1.832 g cm⁻³ at 110K and 1.919 and 1.766 g cm⁻³ at 295 K, respectively), which is provided, in particular, by strong intermolecular hydrogen bonding and π-π stacking interactions. Among substituted azofurazans and primary nitramines examined by X-ray diffraction analysis, 4,4′-bis(nitramino)azofurazan 2 is characterized by the highest density.     

Decarboxylation and electrophilic substitution in 3-tert-butyl-4-oxopyrazolo[5,1-c][1,2,4]triazines

Russian Chemical Bulletin - Reactivity of 7-R-3-tert-butyl-4-oxo-4,6-dihydropyrazolo[5,1-c][1,2,4]triazine-8-carboxylic acids (R = NH2, N3, H) and products of their decarboxylation towards...     

Reactions of 2-alkoxy-3-alkyl-1,3,2-oxazaphosphinanes with alkyl chloroformates

2-Alkoxy-3-alkyl-1,3,2-oxazaphosphinanes containing a sterically hindered N atom react with alkyl chloroformates according to the Arbuzov mechanism only. The ratio of the open and cyclic reaction products depends on the nature of the alkoxy group in the starting phosphinane. With a less hindered N atom, acylation at the N atom gives acyclic chloridophosphites, in addition to the Arbuzov-type products. The structures of the chloridophosphites were confirmed by their chemical transformations into stable thiophosphates. Oxazaphosphinane analogs of phosphorylformamides and phosphorylformohydrazide were obtained.     

The effects of inhomogeneous broadening in an organic microcavity laser

In this work we study the input–output characteristics of an organic vertical cavity surface emitting laser (OVCSEL) with an active layer of Alq3:DCM over 3 orders of magnitude in pump intensity. We find that lasing from this standard inhomogeneously broadened gain medium cannot be described using a single lasing threshold value. Instead, an inhomogeneously broadened distribution of spontaneous emission factors, beta, must be employed in order to correctly model the measured input–output characteristics.     

New 3-Cyano-1,2λ 3 -Thiaphosphacyclanes and Their Complexing Properties

Reduction of both individual diastereomers of 2-oxo-1,2-thiaphosphacyclanes by HSiCl 3 proceeds with retention of cyclic structure, cyano-group, and stereochemical configuration.     

Synthesis and characterization of nonsymmetric cyclopentene-based dithienylethenes

Nonsymmetric cyclopentene-based dithienylethenes, containing both thienyl and benzothienyl units, have been synthesized for the first time, employing intramolecular McMurry reaction as a key transformation to target compounds 10 and 16. Photochromic properties of these compounds were examined in toluene and acetonitrile solutions, PMMA layers, solid films, and crystal phase. To explain an unprecedented single-crystalline photochromism phenomena of 10, X-ray crystallographic analysis was performed, revealing a significant influence of strong S···S interatomic interactions on the intramolecular distance between two photochemical reaction centers in the molecule. Compound 16 could be further synthetically modified in a step-by-step manner, thus serving as potential key intermediate to various complex bifunctional photochromic molecules.     

4,5-Dihydroxyimidazolidin-2-ones in α-ureidoalkylation of N-carboxy-, N-hydroxy-, and N-aminoalkylureas 2. α-Ureidoalkylation of N-(hydroxyalkyl)ureas

Russian Chemical Bulletin - The α-ureidoalkylation of N-(hydroxyalkyl)ureas (ureido alcohols) with 1,3-H2- and 1,3-Me2-4,5-dihydroxyimidazolidin-2-ones was systematically studied. The yields...