80631-72-7

Upstream product

• 100-01-6 4-nitro-aniline 
• 91-66-7 N,N-diethylaniline 
• 80631-73-8 N,N-diethyl-4-((4-nitrophenyl)diazenyl)aniline 

Downstream Products

• 80631-73-8 N,N-diethyl-4-((4-nitrophenyl)diazenyl)aniline 
• 98-95-3 nitrobenzene 
• 100-01-6 4-nitro-aniline 
• 93-05-0 N,N-diethylaniline 
• 90827-99-9 4-Amino-4'-N,N-diethylaminoazobenzen 

Relevant academic research and scientific papers

Supercritical Carbon Dioxide. The Cis to Trans Relaxation and ?,?* Transition of 4-(Diethylamino)-4'-nitroazobenzene

Rates of the cis-trans isomerization of 4-(diethylamino)-4'-nitroazobenzene (DENAB) have been determined for supercritical CO2 media at 32.4 deg C and several densities and DENAB concentrations.A plot of ΔG (excit.) against the Kamlet-Taft ?* parameter has two linear parts, one for the CO2 media and alkanes and another for more polar solvents.The slope for the CO2 and alkanes is positive and small, and that for the other solvents is large and negative.It is suggested that the reaction mechanism in the CO2 media and in alkanes is inversion at one of the azo nitrogens, while in the more polar solvents it is rotation about the bond between the azo nitrogens, for which the transition state is much more polar.The point of intersection of the two lines is at a ?* value of about +0.2.Unlike the ΔG (excit.) values, the Emax of the ?,?* internal charge-transfer band of DENAB are adequately accommodated by a single line

Solvent Effects upon the Thermal Cis-Trans Isomerization and Charge-Transfer Absorption of 4-(Diethylamino)-4'-nitroazobenzene

A comprehensive study of the solvent effects on the rate of the thermal cis-trans isomerization and the position of the charge-transfer absorption of the trans isomer of 4-(diethylamino)-4'-nitroazobenzene (DENAB) is presented.The isomerization rates, the activation parameters, and the absorption maxima have been measured in a variety of protic and aprotic solvents.The data are analyzed and interpreted by using the Taft and Kamlet multiparameter approach and the pyrene fluorescence parameter Py.The results of the correlations suggest that the isomerization reaction is accelerated in hydrogen-bonding solvents relative to aprotic solvents of similar polarity due to a hydrogen-bonding interaction between the solvent and the nitro group of the dye.Correlation of the absorption maxima with the Taft-Kamlet ?* parameter shows a similar dependence in protic and aprotic media.It is apparent that the absorption process is not affected by hydrogen bonding as strongly as the rate of isomerization.A linear correlation of the rate of isomerization with the position of the CT absorption in different solvents is suggestive of the fact that a similar degree of charge transfer exists in the transition state for the isomerization reaction and in the Frank-Condon excited state.

Effect of head group size on the photoswitching applications of azobenzene Disperse Red 1 analogues

We investigate the effect of the increased molecular bulk in the 'head' group for a class of newly synthesized azobenzene chromophores with a clickable ethynyl group para and a nitro group ortho to the azo bond on the distal benzene ring. This 'variable-head' functionalization provides a family of dyes with photophysical characteristics very similar to those of Disperse Red 1, one of the most commonly used azo dyes in materials science. Phenyl, naphthyl, and anthracyl derivatives were synthesized as small molecules, monomers, homopolymers, and copolymers in a rapid and facile manner using click chemistry, confirming the versatility of this parent chromophore. Photochemical and spectral studies indicate that this strategy is suitable to build a 'bulkiness series' of stimuli-responsive materials, as the various material derivatives retain the absorption and kinetic characteristics of the parent chromophore necessary for all optical patterning applications that DR1 dyes have been optimized for. In thin films, larger head group size was found to increase the stability of light-induced birefringence in copolymers. The homopolymers formed stable surface-relief gratings upon interference irradiation, whose grating depths correlate with head group size, demonstrating that this new class of polymers can also undergo tailored macroscopic photoinduced motions, which could have applications in all optical nano-patterning. the Partner Organisations 2014.

The effect of substitution on the dyeing and spectroscopic properties of some monoazo disperse dyes

A range of monoazo disperse dyes has been synthesized. The colour, dyeing and fastness properties of the dyes on polyester, nylon and secondary acetate fibre at 1/1 standard depth have been examined and rationalized in terms of dye structure. The visible absorption behaviour of the dyes was also investigated. In general, substitutions on the diazo component have a significant effect on the visible absorption maxima of the dyes. Increasing the solvent polarity also had a pronounced effect on the absorption maxima.

Rate constants of the thermal cis-trans isomerization of azobenzene dyes in solvents, acetone/water mixtures, and in microheterogeneous surfactant solutions

Rate constants kiso of the thermal cis-trans isomerization of four 4,4′-nitro-aminoazobenzenes with different amino groups have been determined in homogeneous aprotic solvents and polyglykol oligomers, primarily by means of conventional flash photolysis. The rate constants have been correlated with polarity (according to λmax from UV/Vis absorption spectra of the trans isomers) and bulk viscosity of the solvents. Qualitative conclusions about the influence of varying concentrations of water with respect to polarity and hydrogen bonding on kiso- and λmax-values in acetone/water mixtures were derived. Based on these results the data from microheterogeneous solutions have been interpreted. In microheterogeneous water/surfactant solutions kiso-values of selected azo dyes were strongly dependent on the concentrations of SDS, Triton X-100, C12EO8 in water, and varied with the composition of bicontinuous microemulsions of Igepal CA-520/heptane/water. The large spread of isomerization rate constants is in part due to varying microviscosity. Replacement of H2O by D2O in aqueous surfactant solutions produced surprisingly large kinetic solvent isotope effects.

Solubilization Sites and Orientations in Microheterogeneous Media. Studies Using Donor-Acceptor-Substituted Azobenzenes and Bichromophoric Solvatochromic Molecules

A series of p-donor-p'-acceptor-substituted azobenzenes (1-7) has been prepared and their reactivities examined in a variety of homogeneous and microheterogeneous solutions.The series includes several bichromophoric azobenzenes containing a second phenyl or p-nitrophenyl substituent (3-7).Absorption spectra of the trans-azobenzene chromophore are highly solvatochromic in homogeneous solution as are the observed rate constants, kct, for thermal isomerization of photogenerated cis isomers.Good correlations are observed for both properties with a number of empirical solvent polarity parameters, especially the Taft-Kamlet "?*".In oil-continuous reversed micelle solutions (Aerosol OT (sodium bis(2-ethylhexyl)sulfosuccinate)/oil/water), most of the azobenzenes show absorption spectra characteristic of hydrocarbon (nonpolar) solutions but high isomerization reactivity (kct) consistent with a polar environment.The results are analyzed to assess the extent of equilibration between oil and the polar-nonpolar interface or water pool for the isomers of the different azobenzenes.In water-continuous microheterogeneous media (micelles, vesicles, biomembranes), azobenzenes exhibit red-shifted spectra for the azobenzene chromophore and high kct values, consistent with solubilization at very polar sites.The bichromophoric compounds, especially 5, show evidence of differential solvent polarity for the two chromophores, consistent with an interface-spanning solubilization site.

SOLVENT AND SUBSTITUENT EFFECTS ON THERMAL CIS-TRANS-ISOMERIZATION OF SOME 4-DIETHYLAMINOAZOBENZENES

Thermal cis-trans-isomerization of some 4'-substituted 4-diethylaminoazobenzenes has been studied.Substitution in the 4'-position leads invariably to an acceleration of the reaction regardless of the nature of the substituent.Logarithms of kinetic constan