The Comparative Solvatochromism of Arylazo and Heteroarylazo Compounds Based On N,N‐Diethyl‐m‐acetylaminoaniline and N,N‐Diethyl‐m‐toluidine

Abstract

Azobenzene dyes derived from various anilines and aminothiahetcrocycles azo-coupled with commercially important N,N-dicthyl-m-toluidine (T series) and N,N-diethyl-m-acetylaminoaniline (A series) are positively solvatochromic. The visible spectra of 16 pairs or derivatives have bccn measured in up to 22 solvents, and the transition energies related to Kamlet -Taft solvent polarity parameters. In general, A-series dyes are

Bordeaux‐R interactions with surfactants: thermochromic investigations of proton ionisation in cationic, nonionic and anionic surfactant solutions

“…In contrast, Figure 2d indicates that spectra are insensitive to SDS addition. Bathochromic shifts have also been observed with other dyes and have been attributed to their solvation in a less polar environment [4,36–38].…”

Structures, solvatochromism, protonation and photoswitching of tetra-(ortho)substituted azobenzenes bearing 3,5-dimethoxy groups

“…Considering as a measure of this effect Hammett s p values, the expected trend would be ( 9 (2) and ( 3), but the effect is small when this happens in only one ring, cf. ( 10) and (11). In derivatives containing only two methoxy groups, the basicity drops sharply if these groups belong to different rings as in (4), but remains relatively high if they are in ortho positions of the same ring.…”

“…The solvatochromism of donor–acceptor (or push–pull) substituted azobenzenes, involving a combination of strong electron donor and electron acceptor substituents, was studied most thoroughly in terms of the linear solvation energy relationships. 11–16 In this approach the wave number of the absorption maximum max is correlated by multiple linear regression to a set of empirical solvent parameters reflecting different types of intermolecular solvent–solute interactions. The most widely used are three sets of such parameters: Kamlet–Taft parameters (solvent dipolarity/polarizability π*, acidity α, and basicity β), 17 Catalan parameters (solvent acidity SA, basicity SB, polarizability SP, dipolarity SdP), 18 and Laurence parameters (dispersion-induction DI, electrostatic ES, solvent hydrogen-bond acidity and basicity α 1 and β 1 ) 19 with the respective regression eqn (1)–(3). Ñ max = 0 max + s π* + a α + b β max = 0 max + s SP + d SdP + a SA + b SB max = 0 max + di DI + e ES + a α 1 + b β 1 …”

Solvent Effects on the Electronic Spectra of Some Heterocyclic Azo Dyes

“…[15][16][17][18][19][20][21][22] The first examples of negative solvatochromism in neutral azo dyes containing both strongly electron-donating and -withdrawing moieties were reported by Kim et al. 23 temperature.…”