Showing papers on "Triazene published in 2008"
TL;DR: In this article, the growth of the ferrocene-containing multilayer was controlled by molecular concentrations and reaction times, and it was shown that the film thicknesses were in the range of subnanometer to several nanometers.
Abstract: Ferrocene-containing molecules have been grafted to Si(100) surfaces to form monolayers and multilayers via a triazene derivative and its subsequent diazonium chemistry. The growth of the ferrocene-containing films was controlled by molecular concentrations and reaction times. Results from ellipsometry showed that the film thicknesses were in the range of subnanometer to several nanometers. X-ray photoelectron spectroscopy has confirmed the structural integrity of ferrocene in the films. Electrochemical studies of the ferrocene-containing multilayer have shown a reversible one-electron wave of the ferrocene/ferrocenium couple. The multilayer coverage was found to be 2.8 × 10−9 mol cm−2. The calculated electron transfer rate constant was 164 s−1.
29 citations
TL;DR: In this article, a reaction of 1,3-diaryltriazenes (R,C 6 H 4 N N−(NH) with [Rh(PPh 3 ) 3 Cl] in ethanol in the presence of a base (NEt 3 ) affords a family of yellow complexes (1 - R ) containing a PPh 3, two de-protonated triazenes coordinated as bidentate N,N-donors, and an aryl fragment coordinated in the η 1 -fashion.
20 citations
TL;DR: The stability of substituted aryl-3,3-dialkyltriazenes, valuable synthetic intermediates, under several reaction conditions has been evaluated in this article, with special emphasis on strong basic and metal/acid reductive conditions.
12 citations
TL;DR: In this article, it was shown that the extraordinary stability of triazenes formed by an azo coupling reaction of 5-nitrobenzo[c]-1,2-thiazole-3-diazonium with primary or secondary aromatic amines is caused by the fact that these substances are protonated at the heterocyclic nitrogen atom and not at the nitrogen atom of the triazene grouping.
11 citations
TL;DR: In this article, the bichromophoric behavior of 1,3-bis(4-nitrophenyl)triazene anion was investigated by electronic (UV-Vis) and resonance Raman (RR) spectroscopies.
Abstract: Highly delocalized molecular frameworks with intense charge transfer transitions, known as push-pull systems, are of central interest in many areas of chemistry, as is the case of nitrophenyl-triazene derivatives. The 1,3-bis(2-nitrophenyl)triazene and 1,3-bis(4-nitrophenyl)triazene were investigated by electronic (UV-Vis) and resonance Raman (RR) spectroscopies. The bichromophoric behavior of 1,3-bis(4-nitrophenyl)triazene anion opens the possibility of tuning with visible radiation, two distinct electronic states. The RR profiles of nitrophenyl-triazene derivatives clearly show that the first allowed electronic state can be assigned to a charge transfer from the ring π system to the NO2 moiety (ca 520 nm), while the second, as a charge transfer from N3− to the aromatic ring (ca 390 nm). In the para-substituted derivative, a more efficient electron transfer and a greater energy separation between the two excited states are observed. Copyright © 2008 John Wiley & Sons, Ltd.
6 citations
5 citations
TL;DR: In this article, two new triazene monomers, such as (1-( para methoxy-phenyl)-3-(2 acryloyloxyethyl)-3-methyl triazenes, were synthesized and further employed as reaction partners with methyl methacrylate (MMA) in order to investigate the substituent effect of the Triazene moiety on the polymeric properties.
Abstract: Two new triazene monomers, such as (1-( para methoxy-phenyl)-3-(2 acryloyloxyethyl)-3-methyl triazene-1, M 1 ) and (1-( para chloro-phenyl)-3-(2 acryloyloxyethyl)-3-methyl triazene-1, M 2 ) were synthesized and further employed as reaction partners with methyl methacrylate (MMA) in order to investigate the substituent effect of the triazene moiety on the polymeric properties. The synthesized monomers and polymers (PA1, molar fraction of M 1 = 0.16; PA2, molar fraction of M 2 = 0.11) were characterized by analytical and spectroscopic methods, while the surface morphology of polymers was visualized by atomic force microscopy (AFM) and optical microscopy. The photosensitivity of these copolymers was evaluated upon UV exposure, in solution and in film state, following the decreasing value of the π–π * absorption band corresponding to the triazene group centered at 290 nm and 320 nm. For both copolymers, the kinetic data indicated a first-order photoprocess, as evidenced from the determined constant rate in film state (PA1, k = 2.3 × 10 −3 s −1 ; PA2, k = 2.7 × 10 −4 s −1 ). Moreover, the ablation characteristics achieved at low fluence for an irradiation wavelength of 308 nm, quality structuring with no any debris and the absence of carbonization of the irradiated areas suggest that such photolabile polyacrylates could offer new possibilities in printing techniques and nanostructures on surfaces. In addition, the triazene functions introduced as side groups may be used for the tailoring of special polymeric architectures.
5 citations
TL;DR: In this article, a triazene urethane methacrylate was synthesized and characterized to be used as co-partners in the radical co-polymerization with methyl methacylate for achieving triazenes-co-polymethacrylates.
Abstract: New triazene urethane methacrylates, 1 -(phenyl)-3-(2-methacryloyloxyethyl)-3-methyl triazene- 1 (UMA-T1) and 1-(p-methoxyphenyl)-3-(2-methacryloyloxyethyl)-3-methyl triazene-1 (UMA-T2), were synthesized and characterized to be used as co-partners in the radical co-polymerization with methyl methacrylate for achieving triazene-co-polymethacrylates. The synthesized photo-polymers were spectrally and thermally characterized, the results being satisfactory for this class of materials. The most important feature of the co-polyacrylates is their photosensitivity, evaluated by the UV irradiation in DMF solution or thin films, following the disappearance of the π-π* absorption band, corresponding to the triazene chromophore, in the UV spectra. Such photolabile polymers with good film-forming properties could offer new possibilities in printing techniques and nanostructuring on surfaces. In addition, the triazene functions introduced as side-groups may be exploited for the tailoring of novel functional polymeric architectures.
4 citations
TL;DR: The crystal structure of [HgL2], L = 1,3-bis(2-methoxyphenyl)triazene was determined by X-ray diffraction as discussed by the authors.
Abstract: The crystal structure of [HgL2], L = 1,3-bis(2-methoxyphenyl)triazene was determined by X-ray diffraction. The complex crystallizes in the orthorhombic system, space group Pna21 with a = 8.1817(3), b = 15.4123(6), c = 21.1836(8)A, V = 2671.23(17)A3, Z = 4. The structure was solved by the full-matrix least-squares on F2, and had a refined R value of 0.0274 for 6187 reflections (I > 2σ(I)). The Hg atom is coordinated by two molecules of the title ligand via the N(3), N(4) and N(6) atoms in a distorted triangular pyramid geometry.
3 citations
TL;DR: The crystal structure of 1,3-bis(2-cyanophenyl)triazene as mentioned in this paper shows a dimmer formation between two molecules of L through intermolecular hydrogen bonds D-H…(A1, A1′).
Abstract: The crystal structure of the title compound, 1,3-bis(2-cyanophenyl)triazene, shows a dimmer formation between two molecules of L through intermolecular hydrogen bonds D-H…(A1, A1′). The directions of the aromatic rings indicate the presence of strong face-to-face π-π stacking interactions and intermolecular C-H…N hydrogen bonds. These interactions extend the two-dimensional chains further into a three-dimensional network.
3 citations
TL;DR: In this article, the first mononuclear triazenido 1-oxide complex of Ag(I) including a [Ag(PPh3)2]- fragment was obtained.
Abstract: The reaction between [Ag(PPh3)3(NO3)] and 1-phenyl-3-(4-nitrophenyl) triazene 1-oxide desprotonated with potassium hydroxide in methanol yields crystalline [Ag(O2NC6H4NNNOC6H5)(C18H15P)2], the first mononuclear triazenido 1-oxide complex of Ag(I) including a [Ag(PPh3)2]+ fragment. In the asymmetric title complex, the coordination geometry about the Ag+ ion is tetrahedral, with one triazenido 1-oxide anion acting as a bidentate ligand (four-electron donor). The crystal belongs to the monoclinic system, space group P21/c with the cell dimensions a = 19.551(7), b = 19.342(9), c = 11.124(6)A, β = 95.453(15)°, V = 4187(3)A3, Z = 4.
TL;DR: The results indicate that the cis form of triazene has a specific enthalpy of combustion of −15.2 kJ g−1 and the trans form has a Specific enthalpies of combusting of −14.7 k j−1.
Abstract: Following our recent study on triazane, we present a follow-up study on the thermodynamic properties of triazane’s unsaturated analog, triazene. We predict optimized structural parameters, vibrational frequencies, enthalpies of formation, enthalpies of combustion, specific enthalpies of combustion, and proton affinities. Our results indicate that the cis form of triazene has a specific enthalpy of combustion of −15.2 kJ g−1 and the trans form has a specific enthalpy of combustion of −14.7 kJ g−1.
TL;DR: The crystal structure of [Cu2I2L2], L = 1,3-bis(2-methoxyphenyl)triazene was determined by X-ray diffraction as discussed by the authors.
Abstract: The crystal structure of [Cu2I2L2], L = 1,3-bis(2-methoxyphenyl)triazene was determined by X-ray diffraction. The complex crystallizes in the monoclinic system, space group P21/c with a = 9.0976(8), b = 12.4229(12), c = 14.4204(11)A, β = 106.582(3)°, V = 1562.0(2)A3, Z = 2. The structure was solved by the full-matrix least-squares on F2 and had a refined R value of 0.0245 for 3486 reflections (I > 2σ(I)). The Cu2I2 moiety is coordinated by two molecules of the ligand via azide nitrogen and oxygen from a methoxy group in a trigonal pyramidal geometry.
TL;DR: The crystal structure of C15H14N4O3 as mentioned in this paper reveals the expected trans stereochemistry about the N=N double bond in the diazoamine moiety, and the distribution of the double-bond character among the N atoms of the D moiety is unequal, indicating a delocalization of the π electrons over the N-N(H) group toward the terminal 4-carboxyphenyl substituent.
Abstract: The crystal structure of the title compound, C15H14N4O3, reveals the expected trans stereochemistry about the N=N double bond in the diazoamine moiety. The interplanar angle [36.68(6)°] between the terminal phenyl rings indicates that the whole molecule deviates significantly from planarity (r.m.s. deviation = 0.3148 A). Intermolecular O-H…O classical hydrogen bonds, and hydrogen bonds with a bifurcated geometry generate a three-dimensional molecule arrangement. The distribution of the double-bond character among the N atoms of the diazoamine moiety is unequal, indicating a delocalization of the π electrons over the N=N-N(H) group toward the terminal 4-carboxyphenyl substituent.
TL;DR: A series of triazene derivatives with polyfunctional substituents, such as the ylide moiety and ester groups, were synthesized by the reaction of dimethyl acetylenedicarboxylate with 1,3-diaryl-1-triazenes in the presence of triphenylphosphine in ethyl acetate as discussed by the authors.
Abstract: A series of triazene derivatives with polyfunctional substituents, such as the ylide moiety and ester groups, were synthesized by the reaction of dimethyl acetylenedicarboxylate with 1,3-diaryl-1-triazenes in the presence of triphenylphosphine in ethyl acetate.
TL;DR: The X-ray crystallographic study of the title compound, C37H41N3O6, at 150 K establishes the N-oxide form of the triazene 1-oxide unit.
Abstract: The X-ray crystallographic study of the title compound, C37H41N3O6, at 150 K establishes the N-oxide form of the triazene 1-oxide unit There is one intramolecular N—H⋯O hydrogen-bonding interaction and the crystal packing is stabilized by one N—H⋯O, three C—H⋯O and three C—H⋯π intermolecular interactions The dihedral angles between pairs of adjacent benzene rings are 149 (3), 563 (1) and 560 (1)°
TL;DR: In this paper, a new triazene reagent 5-methyl-2-[3-(4-phenylthiazol-2-yl)triazenyl]benzenesulfonic acid (MPTTBSA) and its interaction with N-cetylpyridinium chloride (CPC) was reported.
TL;DR: A wide range of directing groups allow the regioselective directed ortho insertion (DoI) of zinc in the presence of LiCl leading to polyfunctional aryl and heteroaryl zinc reagents.
Abstract: A wide range of directing groups (ester, ketone, acetate, aryl sulfonate, triazene, carbamate) allow the regioselective directed ortho insertion (DoI) of zinc in the presence of LiCl leading to polyfunctional aryl and heteroaryl zinc reagents.