Synthesis and some properties of 1,3,5-triformylbenzene

Conclusions A convenient method was proposed for the synthesis of 1,3,5-triformylbenzene and some of its properties were studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1886–1888, August, 1975.     

Synthesis and structure of new 1,3,5-triazine-pyrazole derivatives

We have studied the reaction of methylenedicarbonyl compounds with 4,6-disubstituted 2-hydrazinyl-1,3,5-triazine in order to obtain novel coupled biheterocyclic aromatic systems with potential bioactivity. Reaction conditions were studied and optimized, and a series of 4,6-disubstituted 2-(1H-pyrazolyl)-1,3,5-triazines were obtained with good yield.     

Synthesis,structure, and dynamic behavior in solution of arylamino-1,3,5-triazines

Ten unsymmetrically substituted arylamino-1,3,5-triazines were synthesized and studied by dynamic NMR spectroscopy. The free energies of the hindered rotation ΔG^≠?are in 59–77 kJ mol^{? 1} range. Using difference-mode NOE NMR experiments, the structures of the major and minor rotation isomers were proved. The DFT B3LYP/6-31G* calculations were performed. The difference between the calculated rotation barriers and the experimental values obtained by line shape analysis is less than 7.6 kJ mol^?1. The height of the rotation barrier varies in a 18 kJ mol^?1 range depending on the substituents in the triazine ring.     

1,3,5-Triazinenitrolic acids. Synthesis and NO-releasing properties

Reactions of salts of 1,3,5-triazine dinitromethyl derivatives with nitrogen dioxide that result mainly in 1,3,5-triazinenitrolic acids are investigated. The behavior of nitrolic acid in electroreduction at a mercury drop electrode at various pH was studied; oxygen was shown to accelerate the process. The promoting effect of nitrolic acids on the activity of soluble guanylate cyclase of human platelets was shown. The studied nitrolic acids are active donors of nitric oxide, a universal and important regulator of cell metabolism functions. NO-releasing properties of furoxans are investigated.     

Nitromethyl derivatives of 1,3,5-triazine. Synthesis and properties

The destructive nitration of 2,4,6-tris[di(carboxy)methylene]hexahydro-1,3,5-triazine and its esters has been investigated. A first representative of the nitromethyl derivatives of 1,3,5-triazine, viz. 2,4,6-tris(nitromethyl)-1,3,5-triazine, has been synthesized.Deceased.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913. Institute of Chemical Physics in Chernogolovka, Russian Academy of Sciences, Chernogolovka 142432. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1254–1259, September, 1997.     

Synthesis,structure, and properties of N-quinoxalylformazans

The first representatives of the previously unknown N-quinoxalylformazans were synthesized. Their chemical properties were investigated, and their structure and chromaticity are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1705–1707, December, 1973.     

1,3,5–三嗪–2,4–二酮衍生物的合成及其晶体结构研究

以尿素和4,5-二氮芴-9-酮为原料合成目标化合物,用1 H NMR、元素分析、FT-IR和X-射线单晶衍射进行了表征.晶体结构表明:化合物为单斜晶系,P21/n空间群,晶体学参数:a=0.710 89(9)nm,b=1.507 39(19)nm,c=1.344 95(16)nm,β=99.741(4)°,V=1.420 5(3)nm3,Z=4,Dc=1.591g·cm-3,Mr=339.16,μ=0.472,F(000)=696,R1=0.085 2,wR2=0.274 8[I2σ(I)].化合物通过氢键形成三维网状结构.     

Synthesis,physical properties,and structure of TIPS-difuranoacenes

The synthesis, physical properties, and structure of triisopropylsilylethynyltetracenodifuran (2) and pentacenodifuran (3) derivatives were reported. There showed high stability in solution in the dark, yet decomposed under light. Single crystal of pentacenodifuran was analyzed by X-ray diffraction analysis, and showed one dimensional packing array along the c-axis. The molecules were stacked with a 3.30 Å interlayer distance. The crystals exhibited a high thermal stability under an ambient condition.     

Synthesis,structure, and properties of isomeric polyaminoacetophenones

In terms of the ability for electrochemical transformations in acidic medium, the reactivity decreases in the order o-aminoacetophenone > p-aminoacetophenone > m-aminoacetophenone > aniline. The products of electrochemical polycondensation of the ortho and para isomers are conductors. Oxidative polycondensation of o-aminoacetophenone forms emeraldin hydrosulfate, and with p- and m-aminoacetophenones, emeraldin and leucoemeraldin are formed. In terms of thermal stability, polyacetoaminophenones can be ranked in the order poly-o-aminoacetophenone > poly-m-aminoacetophenone > poly-p-aminoacetophenone.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 12, 2004, pp. 2012–2018.Original Russian Text Copyright © 2004 by Stratan, Kovalchuk, Blazejowski.This revised version was published online in April 2005 with a corrected cover date.     

Synthesis,structure, and properties of aromatic polysulfides

Polycondensation of haloaromatics and sodium sulfide has been studied. An increase in reactivity of functional groups, a change of the composition of the elementary polymeric unit with a change of the relative amounts of the monomers, and a key role of side-reactions, i.e. intra(molecular) and macrocyclisation, have been revealed. Low-melting isomeric poly(phenylene sulfides), as well as their derivatives, reactive telechelic oligomers, have been prepared. New methods of preparation of poly(arene sulfides) by transarylation of diphenyl sulfide, polymerisation of cyclic aromatic sulfides, or by direct polycondensation of arenes with sulfur under the action of AlCl₃, as well as by polycondensation of aniline with sulfur in the absence of catalysts have been suggested. Structures and properties of newly prepared polymers have been studied.     

Synthesis, structure, and properties of branched polymethacrylates

The methacrylate: branching agent: chain growth regulator optimal ratios that allow the synthesis of branched polymethacrylates via the crosslinking free-radical copolymerization under the regime of conventional or catalytic chain transfer have been estimated. Relationships between the molecular-mass characteristics of the copolymers, their content of intact C=C bonds, the composition of the starting monomer mixture, and the structure of the branching agent and polymer chain growth regulator have been established. The rheological properties of the branched MMA-based copolymers have been studied. It has been shown that the copolymers are characterized by a weaker dependence of reduced viscosity on the polymer concentration in solution than that for the linear PMMA. The diffusion-sorption behavior of the branched polymethacrylates is determined by the content of the branching agent in them.     

Synthesis,structure, and properties of LaSrCuGaO5

The new brownmillerite-related compound, LaSrCuGaO₅, has been synthesized and characterized. It crystallizes in the orthorhombic non-centrosymmetric space group Ima2. The unit cell dimensions are a = 16.383(1) Å, b = 5.5293(7) Å, c = 5.3275(6) Å. The structure is related to perovskite but contains ordered oxygen vacancies within the two-dimensional gallium oxygen layers resulting in tetrahedral coordination of the gallium cations. Other important structural features include buckled copper-oxygen planes, and disorder of the lanthanum and strontium cations over the A-site. Accurate lattice constant measurements reveal an a-axis expansion of 0.17 Å when doped with strontium La_1–xSr_1+xCuGaO₅ (x_max = 0.13). Magnetic susceptibility measurements demonstrate that the compound remains paramagnetic to 4 K.     

Synthesis, structure, and properties of azatriangulenlenium salts

A general synthetic route to novel nitrogen-bridged heterocyclic carbenium ions of the acridinium and triangulenium type has been developed and investigated. The synthetic method is based on nucleophilic aromatic substitution (SNAr) on the tris(2,6-dimethoxyphenyl)carbenium ion (1) with primary amines and, by virtue of its stepwise and irreversible nature, provides a powerful tool for the preparation of a wide variety of new heterocyclic carbenium salts. Several derivatives of the three new oxygen- and/or nitrogen-bridged triangulenium salts, azadioxa- (6), diazaoxa- (7), and triazatriangulenium (4), have been synthesized and their physicochemical properties have been investigated. Crystal structures for compounds 2 b-PF6, 2 d-PF6, 4b-BF4, 4c-BF4, 6e-BF4, and 8 are reported. The different packing modes found for the triazatriagulenium salts are discussed in relation to the electrostatic and space-filling requirements of the ions. The stabilities of the cations 6a, 7b, and 4a, as expressed by their pKR+ values, have been determined in strongly basic nonaqueous solution by use of the C_ acidity function; the values obtained were 14.5, 19.4, and 23.7, respectively. This study further implied that the C_ scale in its present form is unsuitable for the precise determination of pKR+ values beyond 22.     

Synthesis, structure, and properties of allylamino glycosides

Glycosylation of allylamine with D-glucose, D-galactose, and D-mannose in dry primary aliphatic alcohols was studied. The structures of the resulting N-allyl glycosylamines were established, and their reactivities were studied. It was found that N-allyl glycosylamines tend to structural isomerization involving a change in ring size and do not tend to radical polymerization in the presence of azo initiators.     

Synthesis,structure and properties of perimidine spirans

A study was carried out on a new class of photo- and thermochromic spirocyclic cyclohexadienoneperimidines and 4H-naphtholinoneperimidines. The structures of two of these compounds were determined. The lengths of the C_spiro-N bonds were found to be unequivalent; one of these bonds is cleaved in the photo- and thermochromic transformations. The nitrogen atom of the perimidine ring in both compounds was found to have pyramidal configuration with cis arrangement of the unshared electron pairs, while the cyclohexadienone fragments are strongly distorted toward the boat conformation. The nature of the dependence of the photo- and thermochromic properties on their structure and solvent was established.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 702–708, March, 1991.     

Synthesis,structure and properties of fluorinated graphite

Fluorine-graphite intercalation compounds, C₂F to C₁₆F were synthesized by various methods. C-F bonds range from ionic to semi-covalent. These properties of C-F bonding give to fluorinated graphite metallic conductivity, higher hydrophilicity than graphite and high reduction potential. The c-axis and in-plane structures are governed by C-F bonding, fluorine intercalation rate and host graphites.     

Synthesis and steric structure of 2,2-disubstituted 5-phenyl-1,3,5-dioxaphosphorinanes

Conclusions Phenylbis(l-ethoxyalkyl)phosphines and 2,2-disubstituted 5-phenyl-l,3,5-dioxaphosphorinanes, with their conformational equilibrium shifted in the direction of the form with an axial orientation of phenyl at the phosphorus atom, were obtained by the reaction of phenylbis(hydroxymethyl)phosphine with aldehyde and ketone acetals, respectively.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2506–2509, November, 1986.     

Synthesis, structure and properties of metal nanoclusters

Metal nanoclusters have physical properties differing significantly from their bulk counterparts. Metallic properties such as delocalization of electrons in bulk metals which imbue them with high electrical and thermal conductivity, light reflectivity and mechanical ductility may be wholly or partially absent in metal nanoclusters, while new properties develop. We review modern synthetic methods used to form metal nanoclusters. The focus of this critical review is solution based chemical synthesis methods which produce fully dispersed clusters. Control of cluster size and surface chemistry using inverse micelles is emphasized. Two classes of metals are discussed, transition metals such as Au and Pt, and base metals such as Co, Fe and Ni. The optical and catalytic properties of the former are discussed and the magnetic properties of the latter are given as examples of unexpected new size-dependent properties of nanoclusters. We show how classical surface science methods of characterization augmented by chemical analysis methods such as liquid chromatography can be used to provide feedback for improvements in synthetic protocols. Characterization of metal clusters by their optical, catalytic, or magnetic behavior also provides insights leading to improvements in synthetic methods. The collective physical properties of closely interacting clusters are reviewed followed by speculation on future technical applications of clusters. (125 references).     

Synthesis,structure, and characterization of high-energy 4,6-diazido-N-(4,6-diazido-1,3,5-triazin-2-yl)-1,3,5-triazin-2-amine

Chemistry of Heterocyclic Compounds - The high-energy compound 4,6-diazido-N-(4,6-diazido-1,3,5-triazin-2-yl)-1,3,5-triazin-2-amine was obtained in high yield by azidation of...