Triazene

About: Triazene is a research topic. Over the lifetime, 759 publications have been published within this topic receiving 8714 citations. The topic is also known as: Triazene cleavage & 1-triazene.

Brønsted and Lewis acid adducts of triazenes.

Abstract: The synthetic utility of triazenes rests on the fact that the triazene function can be cleaved by Bronsted or Lewis acids, liberating diazonium compounds. However, the preferred coordination site of the acid is still a matter of debate. We have analyzed triflic acid, B(C6F5)3, and PdCl2 adducts of triazenes by NMR spectroscopy and single crystal X-ray crystallography. In all cases, we observe coordination of the acid to the N1 atom of the triazene. This finding is not only of relevance for acid-induced cleavage reactions, but also for metal-catalyzed reactions with triazenes, which are increasingly being used in synthetic organic chemistry.

Synthesis and photochemical investigations of novel bistriazene polyurethanes

Abstract: Two bistriazene monomers, 1,1′[4,4′-diphenyl]-3,3′-di(β-hydroxyethyl, methyl)-bistriazene (T1) and 1,1′[4,4′-diphenylsulfone]-3,3′-di(β-hydroxyethyl, methyl)-bistriazene (T2) were prepared by an electrophilic N – N coupling of substituted aryldiazonium salts with N -methyl-aminoethanol, and further employed as reaction partners for 2,4-toluene diisocyanate (2,4- and 2,6-TDI isomer mixture, 80:20, v/v) or 4,4′ methylene bis(phenylisocyanate) to achieve hard type bistriazene polyurethanes. The synthesized monomers and polymers were characterized by analytical and spectroscopic methods, while the surface morphology of polymers was visualized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Photochemical assessment of the triazene moieties in monomers and polymers was carried out in solution (methanol, DMF) and film state, following the decreasing under UV irradiation of the π–π * absorption band in the corresponding UV spectra, the kinetic evaluation indicating a first order photoprocess. Laser ablation experiments performed at an irradiation wavelength of λ = 308 nm illustrate that bistriazene polyurethanes have a high potential to furnish good quality surfaces intended for microlithography.

Laser induced decomposition of a designed and a commercial polymer studied by ns-interferometry and shadowgraphy

Abstract: Commercially available polymers often exhibit quite poor laser ablation properties for irradiation wavelengths around 248 nm At these wavelengths, the absorption is due to photostable aromatic groups Photolabile triazene polymers were developed to compare the influence of a photolabile group on the laser ablation process The photochemically active triazene group has a strong absorption band at 332 nm, whereas the second absorption maximum at 220 nm is due to the photostable aromatic group By irradiating at 308 nm and 193 nm, the influence of the photochemically active group on the ablation process can be studied The etching of the triazene polymer starts and ends with the laser pulse No surface swelling, which is assigned to photothermal ablation, is detected for fluences above the threshold of ablation The expansion of the laser ablation induced shockwave was measured for the photolabile triazene polymer and the photostable polyimide The speed of the shockwave increases with fluence and is higher for irradiation with 193 nm than with 308 nm A shockwave with equal or higher velocity is observed for the triazene polymer compared with polyimide

Triaziridine. 9. Mitteilung. Ringöffnungen von Triaziridinen

Abstract: Triaziridines. Ring Openings of Triaziridines Eleven triaziridine derivatives were heated at 60° in CDCl3 to obtain information on the tendency towards, resp. the resistance to, ring opening of the N3-homocycle by thermolysis. Among these triaziridines, there are three which contain, as one of the substituents, a methoxycarbonyl group (ester derivatives 1, 5 and 16), three a methyl group (methyl derivatives 18, 24, and 26), three an H-atom (14, 27, and 30), and two a negative charge (31 and 32). The other two substituents in each of these four classes of triaziridines are trans-located i-Pr groups (1, 18, 27, and 31), cis-located i-Pr groups (5, 24, 14, and 32), and a 1,3-cis-cyclopentylidene group (16, 26, and 30). As major products these mild thermolyses, we isolated : from the trans-ester 1 and from the annellated ester derivative 16, the 1-acyl-azimines 2 and 17, respectively, from the cis-ester 5, the 3-acyl-triazene 4, from the trans-methyl derivative 18, the (E)-diazene 19, and hexamine 21, from the cis-methyl derivative 24 the 2-methylazimine 25, both from the trans- and cis-H-derivatives 27, and 14, respectively, the H- triazene 13 and, finally, both from the trans-and cis-anion 31 and 32, respectively – after protonation the H-triazene 13 and – after methylation – the methyl-triazene 33. The same thermolysis of the annellated methyl and H-derivatives 26 and 30, respestively, resulted only in decomposition. These results can be uniformly interpreted with a primary opening of the triaziridine ring by rupture of one of the two types of NN bonds lending to azimines or triazenide anions. Some of the azimines were isolable, namely 2, 17, and 25, and one was spectroscopically observable as an intermediate, namely 11 on the way to the triazene 4. The other azimines are plausible intermediates to the isolated products, namely 15 on the way to 13, and 22 on the way to 19 and 21. The triazenide anion 28 is the evident intermediate on the way to 13 or to 33. The annellated azimines are assumed not be formed from 26 and 30, or then to be be decomposed under the conditions of their formation. We conclude that the triaziridine derivatives 1, 16, and 18 underwent thermal ring opening between N(1) and N(2), while the derivatives 5, 14, 24, 27, 31, and 32 were ruptured between N(2) and N(3); no conclusion was possible on the ring opening of the derivatives 26 and 30. The predominant formation of the (Z)-azimine 2 from the trans-triaziridine 1, and of the (E)-isomer 3 – among the two azimines – from the cis-triaziridine 5 suggests a stereospecificity in the triaziridine ring openings. This would, however, not be expected to be observable in the products from the other triaziridines, since both NN bonds of the azimine 25 and of the anion 28 probably rotate rapidly and since the secondary trans formations of the other primary products are not able to retain configurational information.

1,3‐Bis(p‐fluorophenyl)triazene

Abstract: Molecules of the title compound, C 12 H 9 F 2 N 3 , contain a triazene group (-N=N-NH), having an extended conformation, and are linked by N-H...N hydrogen bonds to form chains.