Showing papers on "Triazene published in 1995"

Triazene oxide-transition metal complexes as hydrosilylation catalysts

Abstract: Organosilicon compounds having Si-bonded hydrogen atoms are reacted with organic compounds having aliphatic multiple bonds in the presence of triazene oxide-transition metal complexes. The triazene oxide-transition metal complexes are activated by heating at temperatures of from 50° C. to 250° C. and/or by irradiation with light.

Photolysis, thermolysis, and protolytic decomposition of a triazene polymer in solution

Abstract: The depolymerization of a triazeno-group containing photopolymer, poly[oxy-1,4-phenyleneazo(methylimino)hexamethylene(methylimino)azo-1,4-phenylene], is investigated in a tetrahydrofuran (THF) solution. Irradiation of the material leads to a clean decomposition of the photolabile polymer, as monitored by UV spectroscopy and gel-permeation chromatography (GPC). As compared to the photolysis in THF solution, the light-induced decomposition rate of a polymer in a polymer film is shown to be much slower. The highly photosensitive triazeno group also decomposes thermally at temperatures above approx. 220°C. The kinetics of thermal degradation of the polymer in substance was investigated at a temperature of 256°C, and monitored by GPC measurements. During this decomposition, one first observes the development of higher molar-mass fractions, which result from grafting reactions of primary radicals. Upon further thermolysis the triazene polymer is completely degraded to low-molar-mass products. The volatile decomposition products were identified by gas chromatography/mass spectrometry (GC/MS) analysis. The protolytic decomposition, which represents the retrosynthesis of the triazene polymer, was studied in a 9:1 mixture of tetrahydrofuran and an aqueous citrate buffer solution. Although the decomposition rate in this solvent mixture is slow, as compared to the depolymerization in diluted hydrochloric acid, a clean decomposition of the triazene polymer is obtained.

Synthesis and characterization of novel triazeno‐group containing photopolymers

Abstract: The synthesis of novel triazeno-group containing photopolymers is described including their characterization by spectroscopic methods, differential scanning calorimetry, and thermogravimetric analysis. Triazene polymers synthesized by a polycondensation reaction between a bisdizaonium salt and a bifunctional secondary amine are well soluble in usual organic solvents. Transparent, light yellow films of these photopolymers may be produced by simple spin-coating and solution-casting techniques. The effect of polymer structural elements on the photolytic decomposition is studied. Depending on the structure of the polymer, thermolysis proceeds either via a one-step or two-step mechanism.

Formation of methyl 2-arylhydrazono-3-oxobutanoates and 2-arylhydrazono-3-oxobutanenitriles during the coupling reaction of arenediazonium ions with methyl 3-aminocrotonate and 3-aminocrotononitrile

Abstract: Reaction of aryldiazonium salts with methyl 3-aminocrotonate (1) affords high yields of the methyl 2-arylhydrazono-3-oxobutanoates (4); analogous diazonium coupling with 3-aminocrotononitrile (2) gives the 2-arylhydrazono-3-oxobutanenitriles (5). The hydrazones are the product of diazonium coupling at the C2-vinylic carbon, concomitant with hydrolysis of the 3-amino substituent to the 3-oxo derivative; there is no evidence for the formation of a triazene (6), which would be the product of N-coupling. All hydrazones (4a–e and 5a–d) have been fully characterized by IR and 1H and 13C NMR spectroscopy; the NMR spectra of the methyl 2-arylhydrazono-3-oxobutanoates (4) suggest the presence of two isomeric intramolecularly H-bonded forms in solution. Selected compounds were further characterized by elemental analysis and mass spectrometry. A mechanism is proposed for the conversion of 1 or 2 into 4 or 5, and these observations are compared with previously reported observations of diazonium coupling reactions wit...

1-(p-carbamoylphenyl)-3,3-dimethyltriazene, an antitumour agent

Abstract: In the crystal structure of the title compound, 4-(3,3-dimethyl-1-triazeno)benzamide, C9H12N4O, (2), the N = N double bond [1.282 (8) A] is 0.030 A shorter than the N--N single bond [1.312 (8) A], but both bonds are shorter than an isolated N--N single bond suggesting that there is double-bond character in each N--N bond, although it is unequally distributed. The molecule adopts a trans geometry around the N = N bond, but there is a significant deviation from planarity between the benzene ring and the plane of the triazene moiety. Compound (2) forms chains in the solid state in which the molecules are linked by C = O...H--N hydrogen bonds between carbamoyl groups. These chains are cross-linked into sheets by hydrogen bonding between the second N--H moiety and triazene units in adjacent chains.

Assignment of N=N Vibrational Frequencies and Tautomeric Effects in the Vibrational Spectra of 1-Aryl-3-alkyl-3-hydroxy-triazenes and Their Platinum Complexes

Abstract: The vibrational frequencies of the N=N stretching mode of 1-aryl-3-alkyl-3-hydroxy-triazenes and their platinum complexes (PtL4; L = triazene) were investigated by FT-IR and FT-Raman spectroscopy. The influence of electron-donating or -withdrawing substituents on the phenyl ring and of different alkyl substituents at the N3 atom on these frequencies was considered. The N=N vibrational frequency is significantly lowered (as a result of the delocalization of the N=N bond over three nitrogen atoms) compared to related compounds. The Pt complexes show a reduced intensity and an increased linewidth in the vibrational spectra. Additionally, the NMR spectra of the 1-aryl-3-alkyl-3-hydroxy-triazenes were recorded in order to show the tautomeric structure of these substances. The hydroxy triazenes preferentially exist in the N1H form. As a consequence, the N=N stretching frequencies of the hydroxy triazenes appear to be influenced by the superposition of two counteracting effects, the delocalization of the N=N bond and tautomerism.

Organosiloxane, its production and crosslinkable organopolysiloxane composition

Abstract: Organosiloxanes containing at least one chemically bonded transition-metal complex of Pt, Pd, Rh, Ru, Os or Ir with a triazene, tetrazene, tetrazadiene, pentazadiene or triazene oxide ligand, are hydrosilylation catalysts which can be activated by light and heat.

Polymers with Triazene Units in the Main Chain

Abstract: Several monomeric and polymeric triazenes have been synthesized and characterized by common methods such as 1H NMR-, IR-, Raman-, UV-spectroscopy, DSC, and GPC. Their thermolysis, photosensitivity, and the effect of H3O+ on their stability have been studied in detail, since those characteristics are very important for an application of these compounds in microlithography.

2-Amino-imidazole derivatives

Abstract: The present invention provides triazene dyes according to formula (I) for use in thermal transfer printing: A--N═N--NRsup1 Rsup2 (I) wherein A is the residue of a diazotisabie heteroaromatic amine, R 1 and R 2 independently represent hydrogen, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aryl group, a substituted aryl group, a cycloalkyl group, a substituted cycloalkyl group, an aralkyl group, or R 1 and R 2 represent the atoms necessary to complete a ring system or a substituted ring system

Thermolysis of 4-Heteroaryl Substituted 5-Azido-1H-1,2,3-triazoles: Competition Between Rearrangement and Decomposition.

Abstract: 5-Azidotriazoles bearing a thiazole, benzothiazole or pyridine ring at the 4-position were synthesized and thermolyzed at 60°C. Whereas the 5-azido-4-(thiazol-2-yl)triazole 4 decomposed with extrusion of nitrogen and formation of the triazene 5 as the sole reaction product, the 5-azido-4-(benzothiazol-2-yl)triazoles 11a,b furnished mixtures of the triazenes 12a,b and the tetrazoles 14a,b. In the case of the 5-azido-4-(2-pyridyl)triazoles 17a-d, the product distribution was found to depend strongly on the N-1 aryl substituent, favouring the tetrazole 20 by increasing the electron-withdrawing capacity of this group.