Hydrogen bonding in polyamino‐polyalcohols: a monohydrated cocrystal of 1,3‐diamino‐5‐azaniumyl‐1,3,5‐trideoxy‐cis‐inositol iodide and 1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol

In the title monohydrated cocrystal, namely 1,3‐diamino‐5‐azaniumyl‐1,3,5‐trideoxy‐cis‐inositol iodide–1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol–water (1/1/1), C₆H₁₆N₃O₃⁺·I⁻·C₆H₁₅N₃O₃·H₂O, the neutral 1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol (taci) molecule and the monoprotonated 1,3‐diamino‐5‐azaniumyl‐1,3,5‐trideoxy‐cis‐inositol cation (Htaci⁺) both adopt a chair conformation, with the three O atoms in axial and the three N atoms in equatorial positions. The cation, but not the neutral taci unit, exhibits intramolecular O—H...O hydrogen bonding. The entire structure is stabilized by a complex three‐dimensional network of intermolecular hydrogen bonds. The neutral taci entities and the Htaci⁺ cations are each aligned into chains along [001]. In these chains, two O—H...N interactions generate a ten‐membered ring as the predominant structural motif. The rings consist of vicinal 2‐amino‐1‐hydroxyethylene units of neighbouring molecules, which are paired via centres of inversion. The chains are interconnected into undulating layers parallel to the ac plane, and the layers are further held together by O—H...N hydrogen bonds and additional interactions with the iodide counter‐anions and solvent water molecules.     

Theoretical study of the optical and charge transport properties of star-shaped molecules with 1,3,5-triazine-core derivatives as organic light-emitting and organic solar cells materials

A series of D–π–A star-shaped molecules has been investigated theoretically by using density functional theory (DFT) to reveal their optical, electronic, and charge transport properties for applications in organic light-emitting diodes (OLEDs) and organic solar cells (OSCs). The calculated results show that their optical, electronic, and charge transport properties are affected by the different end groups and π-bridges. Our results reveal that the molecules under investigation can serve as OSCs donor materials and/or luminescent materials for OLEDs. In addition, all molecules are expected to be promising candidates for hole- and electron-transport materials. On the basis of the obtained results, we propose a rational way for the design of multifunctional materials for OLEDs and OSCs applications.     

Hyperbranched polyesters based on polycondensation of 1,3,5‐tris(2‐hydroxyethyl) cyanuric acid and 3,5‐dihydroxybenzoic acid

A series of hyperbranched polyesters was produced by the condensation of the monomer 3,5‐dihydroxybenzoic acid with 1,3,5‐tris(2‐hydroxyethyl) cyanuric acid as a trifunctional central core. The monomer‐to‐core ratio was varied between 3 and 45. The resulting polymers were phenolic‐terminated polyesters. The degree of branching of the polyesters was calculated according to the method described by Fréchet and was found to be in the range of 0.7–0.8. The number‐average molecular weights calculated via ¹H NMR spectroscopic degree‐of‐polymerization values are in reasonable agreement with the predicted values derived from the monomer‐to‐core ratio for all prepared polyesters. Thermal and photophysical properties were also studied. Glass‐transition temperatures were determined by differential scanning calorimetry and were found to be relatively independent of the theoretical molar mass. The polyesters were found to be blue emitters, and the solutions exhibited intense fluorescence, with a maximum of 430 nm. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3278–3288, 2005     

Ruthenium, osmium and rhodium complexes of polypyridyl ligands: Metal-promoted activities, stereochemical aspects and electrochemical properties

This article presents a brief overview of the reactions of2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) in presence of rhodium(III), ruthenium(II) and osmium(II) under various experimental conditions. Under certain experimental conditions tptz exhibits metal-assisted hydrolysis/hydroxylation at the triazine ring. However, synthetic methods have also been developed to prepare complexes with intact tptz. Molecular structures of some of the complexes, especially stereoisomers of the hydroxylated products, are established by single crystal X-ray studies. A critical analysis of all data suggests that the electron-withdrawing effect of the metal ion (L→Mσ donation) is the predominant factor, rather than angular strain, that is responsible for metal-promoted reactivities. Electrochemical properties of all of these complexes have been investigated, Rh(III) complexes are excellent catalysts for electrocatalytic reduction of CO₂, and dinuclear Ru(II) and Os(II) complexes exhibit strong electronic communication between the metal centres.     

TATB/聚三氟氯乙烯复合材料力学性能的MD模拟

用分子动力学(MD)方法,对聚三氟氯乙烯(PCTFE)在1,3,5 三氨基 2,4,6 三硝基苯(TATB)晶体表 面的行为进行模拟计算,求得结合能和静态力学性能(弹性系数、模量和泊松比).发现以氢键为主的分子间相互 作用相当强.TATB基氟聚合物粘结炸药(PolymerBondedExplosive,PBX)较TATB单体炸药的力学性能改变很 大,拉伸模量、体积模量和剪切模量均减小,表明刚性减弱,弹性增强,力学性能显著改善.     

Kröhnke pyridines: an efficient solvent-free synthesis of 2,4,6-triarylpyridines

A simple and efficient synthesis of 2,4,6-triarylpyridines is described from a novel reaction between chalcones and ammonium acetate under solvent-free conditions in excellent yields.     

Synthesis of 1,1,1,7,7,7-hexafluoroheptane-2,4,6-trione, the simplest fluorinated 1,3,5-triketone

A simple, convenient and effective method to synthesize 1,1,1,7,7,7-hexafluoroheptane-2,4,6-trione, the simplest fluorinated 1,3,5-triketone, on a preparative scale was developed. The title compound was obtained by a Claisen-type double condensation of acetone with trifluoroacetic acid ethyl ester and isolated as a solid monohydrate from the reaction mixture. Subsequent dehydration proceeds smoothly to produce the desired compound as an individual substance. Its peculiar tautomeric (keto-enol, ring-chain) features in various solvents are discussed.     

Nucleophilic addition to the double bond of 2,4,6-trinitrostyrene and transformations of adducts

Conditions were found under which 2,4,6-trinitrostyrene derived from 2,4,6-trinitrotoluene adds nucleophiles (thiophenol, aniline, and aliphatic amines) at the vinyl fragment to form the corresponding β-X-ethyl-2,4,6- trinitrobenzenes (X = PhS, PhNH, or R₂N). In the reactions with primary aromatic amines, the initially formed adducts undergo intramolecular replacement of the nitro group followed by aromatization of the indolines that formed to the corresponding N-substituted 4,6-dinitroindoles. Dedicated to Corresponding Member of the Russian Academy of Sciences E. P. Serebryakov on the occasion of his 70th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 1022–1025, April, 2005.     

A 3-D open network constructed from metallamacrocycle chains with a simple ‘corner’ ligand of 2,4-diamino-6-methyl-1,3,5-triazine(dmt) via cross-linked hydrogen bonds

The title polymer Ag(I) complex was synthesized through the reaction of 2,4-diamino-6-methyl-1,3,5-triazine(dmt) and Ag₂SO₄. X-ray structure analysis shows that the crystal structure of title complex consists a infinite 1-D polymer chains with novel metallamacrocycles, which are cross-linked to each other by four types of hydrogen bonds, resulting in the formation of a new 3-D open network with large channels.     

Electrooxidation of 1,3–di(para-tolyl)-5-para-toluidinomethyl-1,3,5-diazaphosphorinane on soluble metallic anodes

Electrochemical oxidation of 1,3–di(para-tolyl)-5-para-toluidinomethyl-1,3,5-diazaphosphorinane on various soluble metallic anodes (Al, Cu, Ni) was investigated. Influence on the electrochemical process of such factors as the nature of the metal, anode potential of electrolysis and amount of the passed electricity was established.