The synthesis and some properties of nylon 4,T

The synthesis of nylon 4,T from tetramethylenediamine and a terephthalic acid derivative was studied in a two step-process: prepolymerization, followed by postcondensation in the solid state (4 h, 290°C). The prepolymers were prepared by the nylon salt method, ester polymerization method, interfacial method, and a low temperature solution method. A maximum η_inh of 1.52 was obtained. From a solution in trifluoroacetic acid, films were cast and on these films we studied its IR spectrum, WAXS, and melting behavior with DSC. A boiled up sample had a double melting transition at 434 and 475°C and a ΔH₀ of 130 J/g.     

The synthesis and properties of some derivatives of 2-oxo-4-thioxo- and 2, 4-dithioxo-1h, 3h-pteridines

Some new derivatives of 2-oxo-4-thioxo- (I) and 2,4-dithioxo-1H, 3H-pteridine (II) have been prepared by treatment of 2,4-dioxo- (III) and 2-thioxo-4-oxo-1H,3H-pteridines (IV) with P₂S₅ in dioxane solution. The corresponding 4-phenylhydrazones, and the products of reaction of the pteridinethiones with aliphatic and aromatic amines and amino acids, have been obtained.     

4-amino- and 4-nitrodipicolinatovanadium(V) complexes and their hydroxylamido derivatives: synthesis, aqueous, and solid-state properties

A number of 4-substituted, dipicolinatodioxovanadium(V) complexes and their hydroxylamido derivatives were synthesized to characterize the solid state and solution properties of five- and seven-coordinate vanadium(V) complexes. The X-ray crystal structures of Na[VO2dipic-NH2].2H2O (2) and K[VO2dipic-NO2] (3) show the vanadium adopting a distorted, trigonal-bipyramidal coordination environment similar to the parent coordination complex, [VO2dipic]- (1), reported previously as the Cs+ salt. The observed differences in the chemical shifts of the complexes both in the 1H (ca. 0.7-1.4 ppm) and 51V (ca. 1-11 ppm) NMR spectra were consistent with the electron-donating or electron-withdrawing properties of the substituent groups, respectively. Stoichiometric addition of a series of hydroxylamine ligands (H2NOH, MeHNOH, Me2NOH, and Et2NOH) to complexes 1-3 led to the formation of seven-coordinate vanadium(V) complexes. The X-ray crystal structure of [VO(dipic)(Me2NO)(H2O)].0.5H2O (1c) was found to be similar to the previously characterized complexes [VO(dipic)(H2NO)(H2O)] (1a) and [VO(dipic)(OO-tBu)(H2O)]. While only slight differences in the 1H NMR spectra were observed upon addition of the hydroxylamido ligand, the signals in the 51V NMR spectra change by up to 100 ppm. The addition of the hydroxylamido ligand increased the complex stability of complexes 2 and 3. Evidence for a nonstoichiometric redox reaction was found for the monoalkyl hydroxylamine ligand. The reaction of an unsaturated five-coordinate species with a hydroxylamine to form a seven-coordinate vanadium complex will, in general, dramatically increase the amounts of the vanadium compound that remain intact at pH values near neutral.     

The synthesis and properties of dichloroheptafluoropropyltripyridinechromium(III) and some related compounds

The reaction between C₃F₇I and CrCl₂(CH₃CN)₂ in the presence of pyridine allows the isolation of C₃F₇CrCl₂py₃ together with a CrICl₂-pyridine complex. Similar complexes can be prepared using 2,2′-bipyridyl, 2,2′,2″-terpyridyl and 1,10-phenanthroline. The latter complexes are resistant to hydrolysis whereas C₃F₇CrCl₂py₂ is rapidly hydrolysed to a pentafluoroalkyl aquo species.     

The synthesis and liquid crystal properties of some 4-n-nonylphenyl esters of 3-(4'-n-alkoxybiphenylyl)- and 3-(4'-n-alkoxybiphenylyl)-3-methyl-propanoic acids and their laterally fluorinated analogues

A number of 4-n-nonylphenyl esters and mono- and di-fluorinated 4-n-nonylphenyl esters derived from 3-(4'-n-alkoxybiphenylyl)propanoic acids (II) have been synthesized and their thermotropic liquid crystal properties assessed with a view to obtaining tilted smectic phases for possible use in ferroelectric display devices. Many of these compounds exhibit wide temperature range S_C and S_I/F phases, but none gave the ideal phase sequence S_C-S_A-N-I mainly because the structure of these compounds was not conducive to the formation of the nematic phase. To try to alleviate this problem a series of 4-n-nonylphenyl esters based on 3-(4'-n-alkoxybiphenylyl)-3-methylpropanoic acid was prepared, where a lateral methyl group was incorporated in the β-position of the -CH₂CH₂CO₂- linkage. Incorporation of the lateral methyl group encouraged the formation of a nematic phase at the expense of both the smectic A phase and tilted smectic phases.     

The rearrangement of some cyclopentanone-aryloximes: synthesis of (±)-aplysin, (±)-filiformin and of their debromo analogues.

Upon acid catalyzed rearrangement after Sheradsky, the aryloximes A gave the tricyclic aminals C, which suffered hydrolysis to lactols E. The unique alcohol 29 was then prepared through a highly stereoselective equilibration-reductive alkylation of the epimeric mixture of lactols 22a,b. Two routes, one of which was stereospecific, allowed cyclization of 29 to (±)-aplysin 34. The yield was 2.5 % from oximes 2a,b. The isomeric epi-aplysin 35 and filiformin 36 were also obtained from 29. The debromo analogues 37,38 and 39 and their trideutero derivatives 41,42 and 43 were synthesized along similar line and allowed unequivocal structure elucidation by NMR spectroscopy.     

Bis(fluoroalkyl)acrylic and methacrylic phosphate monomers, their polymers and some of their properties

Ten fluoromonomers of structure (R_FO)₂P(O)OCH₂CH₂OC(O)CRCH₂ were made in 30-64% yield by treating the chloridates (R_FO)₂P(O)Cl with HOCH₂CH₂OC(O)CRCH₂ in chloroform in the presence of triethylamine [R_F=CF₃CH₂, C₂F₅CH₂, C₃F₇CH₂, C₄F₉CH₂, C₄F₉CH₂CH₂ or C₆F₁₃CH₂CH₂; R  H or Me]. The chloromonomer (CCl₃CH₂O)₂P(O)OCH₂CH₂OC(O)CHCH₂ was obtained analogously in 29% yield. Polymerisation of the acrylate monomers, but not the methacrylate monomers, could be effected using α-azoisobutyronitrile as a radical initiator. Acrylic polymers having CF₃CH₂O, CCl₃CH₂O and C₆F₁₃CH₂CH₂O side-chains were obtained as translucent rubbers. Specimens of cotton fabric were treated with solutions of the polymers, and average water and oil repellency ratings measured. Fabric coated with the polymer with the C₆F₁₃CH₂CH₂O side-chain afforded protection from penetration of the test liquids. Treated fabrics were subjected to the limiting oxygen index (LOI) test according to BS EN ISO 4589-2 (1999): this test determines the point at which a material just burns in a volumetric flow of oxygen and nitrogen. The treated fabrics were more fire-resistant (LOI 22-29%) than the untreated fabric (LOI 18%). Fabric coated with the CCl₃CH₂O-based polymer can be considered fire-retardant (LOI 29%). The fluoromonomers were tested for anti-acetylcholinesterase activity and were found to be poor enzyme inhibitors; they are predicted to possess low acute toxicity.     

4-Hydroxy-1(2H)-isoquinolone-3-carboxamides synthesis and properties

Reaction of some α-phthalimidoacetamides 1a-i with sodium ethoxide was carried out under drastic conditions. Compounds 1b-g afforded 4-hydroxy-1(2H)-isoquinolone-3-carboxamides 2b-g , while 1h-i afforded the acid 3a-b together with the expected isoquinolones 2h-i. Compound 1a gave phthalimide as the major product. Compounds 2 are acidic and unstable in basic media. The most acidic compounds presented the longest half-life. An explanation of these results was given.     

1-取代酰基-4-磷酰基氨基硫脲及其1, 3, 4-恶二唑杂环衍生物 的合成

合成了1-取代酰基-4-磷酰基氨基硫脲(5),以及由(5)衍生的环化产物2-磷酰氨基-5-苯基(或氰乙基)-1,3,4-恶二唑(6),它们的结构经^1HNMR,IR和元素分析的证实。初步生测结果表明,部分化事物具有一定的植物生长调节活性和除草活性。     

(3,5-Diallylisocyanuratomethyl)phosphine oxides and some of their properties

Reaction of sodium diallylisocyanurate with tris(chloromethyl)-, bis(chloromethyl)phenyl-, and (chloromethyl)diphenylphosphine oxides yields, depending on the stoichiometric ratio of the reagents, mono-, bis-, and tris(3,5-diallylisocyanuratomethyl)phosphine oxides.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Science Center, Russian Academy of Sciences, 420083 Kazan, Tatarstan, Russia. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 12, pp. 2773–2777, December, 1992.     

Tetrakis(4-bromophenoxy)phthalocyanine,its metal complexes,and their sulfonated derivatives: the synthesis and spectral properties

Russian Chemical Bulletin - Tetrakis(4-bromophenoxy)phthalocyanine and its metal complexes (M = Mg, Co, Cu, Zn) were synthesized. Sulfochlorination of these compounds followed by hydrolysis of the...