Showing papers on "Triazene published in 2001"

Hair-dye composition

Abstract: A hair dye composition containing a triazene dissociative direct dye represented by general formula (1): A-N=N-NH-B (1) wherein A and B are each a monocyclic or a bicyclic aromatic heterocyclic group that may have a substituent or a monocyclic or a bicyclic aryl group that may have a substituent and contain none of a carboxy group, a sulfo group and a quaternary ammonium group; and A and B each bind to a triazene-1,3-diyl group represented by -N=N-NH- via a carbon atom within A and B each. A and B may be the same or different.

Hyperbranched Poly(triazene ester)s as Novel Globular Photolabile and Thermolabile Polymers

Abstract: Novel hyperbranched poly(triazene ester)s have been synthesized. These polymers represent a class of polymers with photo- and thermally labile moieties in each repeating unit. For the synthesis suitable AB2 monomers containing these labile units have been designed. The polyesterification was performed at room temperature using 4-(dimethylamino)pyridinium 4-tosylate (DPTS) as catalyst and diisopropylcarbodiimide (DiPC) as activating agent. The polymers have been characterized by FAB-MS, SEC, DSC and 1H/13C NMR spectroscopy. The degree of branching was determined by quantitative high resolution 13C NMR experiments and found to be 0.5. The thermal and photochemical stability of this polytriazenes has been investigated by UV/VIS spectroscopy and thermogravimetric analysis.

A new and simple synthesis of N-succinimidyl-4-[127/125I]iodobenzoate involving a microwave - accelerated iodination step

Abstract: A short and simple method for the preparation of N-succinimidyl-4-iodobenzoate 3 and its 125I analogue that is widely used for radioiodination of proteins is described. The method involves the reaction of in situ generated trimethylsilyl iodide [127I or 125I] from trimethylsilyl chloride with N-succinimidyl-4-[3,3-(1,4-butanediyl)-triazene] benzoate 2 available from the condensation of N-hydroxysuccinimide and 1-(4-carboxyphenyl)-3,3-(1,4-butanediyl)-triazene 1 in the presence of dicyclohexyl carbodiimide (DCC). The new triazene 1 was prepared by precipitating the diazonium ion of 4-aminobenzoic acid with pyrrolidine. A microwave-mediated rate acceleration was observed during the iodination step and by applying this procedure the labelled compound 3 was obtained in 81% radiochemical yield in 8 minutes. Copyright © 2001 John Wiley & Sons, Ltd.

The photochemical reactions of nitrogen-rich mesoionic 1,3-diphenyltetrazolium heterocycles and related compounds

Abstract: Photochemical reactions of azo and triazo derivatives of mesoionic 1,3-diphenyltetrazolium heterocycles and related compounds were studied. The reaction paths were found to depend markedly on the types of substrate, substituent and reaction solvent giving diverse products. Upon irradiation of the 1,1′3,3′-tetraphenylazoditetrazolium salt 1, the addition of hydrogen and acetone to the NN bond was observed in methanol and acetone, respectively, whereas the bond was cleaved in diethyl ketone to give the 5-aminotetrazolium salt 10. The corresponding radical cation 11 also gave the reduction product in methanol. On the other hand, the 1,3-diphenyl-5-(phenylazo)tetrazolium salt 12 underwent nitrogen evolution giving the 1,3-diphenyltetrazolium salt 13via the corresponding tetrazolium radical. Triazene derivatives 14 and 17 underwent an N–N bond cleavage to give tetrazolio-5-amide 4. The mesoionic triazene compounds bearing a tosyl 18 or cyano group 19 gave products 20 and 23. Triphenylphosphinotriazene 24 liberated nitrogen to give phosphinoimide 25 and its hydrolysis product 10. Tetrazolylamide 26 lost a phenyldiazonium group from the 1,3-diphenyltetrazolium ring to give the guanidine derivative 27.

A molecular recognition event in the reaction of a diazonium salt with N, N-dimethylethylenediamine

Abstract: Diazotization of p-aminobenzonitrile and coupling of the resulting diazonium salt with N,N-dimethylethylenediamine affords a novel material that has been shown by X-ray crystallography to be a cocrystal (3) of the pentaazadiene (1) and the diaryltriazene (2). Crystal data: monoclinic, space group P21/c, a = 9.363(5), b = 21.509(3), c = 15.862(5) A, β = 98.86(5)°, V = 3156.3(18) A3, Z = 4, Rw = 0.035, Rint = 0.037. The pairing of the two molecules 1 and 2 appears to represent a unique molecular recognition event involving a combination of hydrogen bonding and π–π stacking. The crystal structure shows that the N–H of the triazene is within hydrogen-bonding distance of the tertiary nitrogen atom in the alkyl side-chain of the pentazadiene; furthermore, the benzene rings of the triazene and the pentazadiene are stacked off-register and separated by 3.53 A. The formation of the components of the cocrystal is rationalised in terms of the formation and decomposition of the 1-aryl-3-alkyltriazene, Ar–N=N–NH–CH2CH2NH2.

The application of the resonance enhanced rayleigh light-scattering technique for the determination of gold(iii) with a new triazene reagent

Abstract: The resonance Rayleigh light-scattering (RRLS) signal of a new triazene reagent, 1-(p-chlorophenyl)-3-(2-thiazolyl)triazene (p-ClPTT), is first synthesized and characterized in this paper, in the 450–550 nm wavelength range is enhanced remarkably by Au3 +. A new method for the determination of Au3 + by the RRLS technique in the presence of Tween-20 has been developed. The calibration graph shows good linearity over a concentration range of 5.0–800 μg/l with a detection limit of 3.0 μg/l. Except for IO4 −, SCN− and Pd2+, no other foreign ions interfere in the determination at concentrations less than 10-fold of Au3 +. The method is thus simple, sensitive and of good selectivity, and has been successfully used for the determination of trace gold in the ore samples.

Nitrogen source for depositing organic metal including triazene derivative or tetrazene derivative and nitride semiconductor device including nitride layer using the same

Abstract: PURPOSE: A nitrogen source for depositing an organic metal including a triazene derivative or tetrazene derivative is provided to improve energy efficiency by making nitrogen within a temperature range from 600 to 800 deg.C to form a nitride layer of an excellent crystal at a low temperature. CONSTITUTION: A nitrogen source for depositing an organic metal is composed of a triazene derivative or tetrazene derivative in which at least one hydrogen of triazene or tetrazene is replaced by a dimethylamine radical. A nitride semiconductor device includes a nitride layer formed by receiving nitrogen from the nitrogen source for depositing the organic metal.

Amination of 1-Arylazo-4-chloroanthraquinones *

Abstract: The simplest 1-arylazoanthraquinones have been known for a long time [1]. (4-Hydroxyphenylazo)anthraquinones typically give rise to azo3quinonehydrazone tautomerism [2], while the other chemical properties of these compounds were poorly studied. Taking into account high reactivity of various halogen-substituted anthraquinones in nucleophilic amination [3], we have examined the reactions of 4-chloro-1-(4-hydroxyphenylazo)anthraquinone (Ia) and 4-chloro-1-(4-dimethylaminophenylazo)anthraquinone (Ib) with cyclohexylamine, morpholine, and piperidine. Compounds Ia and Ib reacted with highly nucleophilic amines in dimethylformamide at 603 80oC and in dimethylacetamide at 50360oC within several hours (Scheme 1). The reactions with weakly nucleophilic amines required more severe conditions and were not selective. We failed to synthesize 4-amino-1-arylazoanthraquinones by the other method, namely by reaction of diazotized 1-amino-4-RNH-anthraquinones with phenol or dimethylaniline. In all cases, products of other transformations were isolated instead of the expected azo coupling products. For instance, from diazotized 1-amino-4-cyclohexylaminoanthraquinone and phenol in dimethylformamide we obtained 1,1-dimethyl-3-(9,10-dioxoanthracen-1-yl)triazene. When dimethylformamide was replaced by water, the product was 1-cyclohexylaminoanthraquinone. The latter was also obtained by attempted azo coupling of the same diazonium salt with N,N-dimethylaniline in dimethylformamide. The structure of compounds IIa3IIc and III was confirmed by elemental analyses and IR, H NMR, and mass spectra. 1-Cyclohexylamino-4-(4-hydroxyphenylazo)anthraquinone (IIa). A mixture of 1.1 mmol of anthraquinone Ia [4], 11 mmol of cyclohexylamine, and 5 ml of dimethylacetamide was stirred at 50360oC for 4 h (until initial anthraquinone Ia disappeared according to the TLC data). The mixture was cooled to room temperature and diluted with water. The dark brown tar-like precipitate was filtered off, washed with water and aqueous ethanol, dried, and subjected to column chromatography on silica gel (40/100 mm)