“…Figure 4 shows a comparison of the absorption spectra obtained theoretically and experimentally as determined in DMSO. In this case, two analogues of the BS2 and BS3 molecules were used, investigated earlier by Zakerhamidi et al [ 67 ]. The difference between them lies in the replacing of the pyrimidine ring with 1,2,5-oxadiazole, leaving the residual skeleton of the compounds.…”
Section: Resultsmentioning
confidence: 99%
“… Fig. 4 Comparison of the absorption spectra determined experimentally [ 67 ] ( blue line ) and theoretically ( green line ) based on the functional PBE0 for BS2 ( left panel ) and BS3 ( right panel ) determined in dimethylsulfoxide (DMSO). In order to reproduce the absorption band, 30 electronic transitions were taken into account.…”
The absorption and emission spectra of three azo sulfonamide compounds in different solvents were investigated theoretically by using response functions combined with density functional theory (DFT), while the solvent effect on the structure and the electronic transitions was determined using the integral equation formalism for the polarizable continuum model (IEF-PCM). The results show that the applied different exchange-correlation functionals can reproduce the experimental values well. DFT calculations of the title compounds showed that the H-bond formed between the solute and solvent molecules is one of the major causes of the reversible solvatochromism observed in measured spectra. This is due to a better stabilization of the neutral form than the zwitterionic form in the polar protic solvents, which is characteristic of the hypsochromic shift. On the other hand, the molecules considered exhibit a monotonic behavior regarding the polarity of the low-lying excited state (Δμg–CT) as a function of the solvent polarity. This dependence occurs in the case of the positive solvatochromism and confirms the thesis regarding the H-bond solute–solvent interactions. Theoretically determined values of the two-photon cross section revealed that the (σOF(2)) shows similar trends with changes in λabs, in contrast to 〈δOF〉 values. In conclusion, the results demonstrate that the investigated molecules can be used successfully as fluorochromes in bioimaging.Electronic supplementary materialThe online version of this article (doi:10.1007/s00894-015-2651-z) contains supplementary material, which is available to authorized users.
“…Figure 4 shows a comparison of the absorption spectra obtained theoretically and experimentally as determined in DMSO. In this case, two analogues of the BS2 and BS3 molecules were used, investigated earlier by Zakerhamidi et al [ 67 ]. The difference between them lies in the replacing of the pyrimidine ring with 1,2,5-oxadiazole, leaving the residual skeleton of the compounds.…”
Section: Resultsmentioning
confidence: 99%
“… Fig. 4 Comparison of the absorption spectra determined experimentally [ 67 ] ( blue line ) and theoretically ( green line ) based on the functional PBE0 for BS2 ( left panel ) and BS3 ( right panel ) determined in dimethylsulfoxide (DMSO). In order to reproduce the absorption band, 30 electronic transitions were taken into account.…”
The absorption and emission spectra of three azo sulfonamide compounds in different solvents were investigated theoretically by using response functions combined with density functional theory (DFT), while the solvent effect on the structure and the electronic transitions was determined using the integral equation formalism for the polarizable continuum model (IEF-PCM). The results show that the applied different exchange-correlation functionals can reproduce the experimental values well. DFT calculations of the title compounds showed that the H-bond formed between the solute and solvent molecules is one of the major causes of the reversible solvatochromism observed in measured spectra. This is due to a better stabilization of the neutral form than the zwitterionic form in the polar protic solvents, which is characteristic of the hypsochromic shift. On the other hand, the molecules considered exhibit a monotonic behavior regarding the polarity of the low-lying excited state (Δμg–CT) as a function of the solvent polarity. This dependence occurs in the case of the positive solvatochromism and confirms the thesis regarding the H-bond solute–solvent interactions. Theoretically determined values of the two-photon cross section revealed that the (σOF(2)) shows similar trends with changes in λabs, in contrast to 〈δOF〉 values. In conclusion, the results demonstrate that the investigated molecules can be used successfully as fluorochromes in bioimaging.Electronic supplementary materialThe online version of this article (doi:10.1007/s00894-015-2651-z) contains supplementary material, which is available to authorized users.
“…The Stokes' shift data also explain the stabilization of the solute molecules in the excited state. Because of this, there is a change in the dipole moment of the dyes upon excitation …”
The UV/Vis absorption and fluorescence characteristics of 3-cyano-7-hydroxycoumarin [CHC] and 7-amino-4-methyl-3-coumarinylacetic acid [AMCA-H] were studied at room temperature in several neat solvents and binary solvent mixtures of 1,4-dioxane/acetonitrile. The effects of solvent on the spectral properties are analyzed using single and multi-parameter solvent polarity scales. Both general solute/solvent interactions and hydrogen bond interactions are operative in these systems. The solvation of CHC and AMCA-H dyes in 1,4-dioxane/acetonitrile solvent mixtures has been studied. The solutes CHC and AMCA-H are preferentially solvated by acetonitrile and a synergistic effect is observed for both molecules in dioxane/acetonitrile solvent mixtures. In addition, using the solvatochromic method the ground- and the excited-state dipole moments of both the dyes were calculated. The ground- and excited-state dipole moments, absorption and emission maxima and HOMO-LUMO gap were also estimated theoretically using B3LYP/6-311+ G (d,p) level of theory in the gaseous phase, dioxane and acetonitrile solvents. Furthermore, changes in dipole moment values were also calculated using the variation of Stokes shift with the molecular-microscopic empirical solvent polarity parameter ( ETN). The observed excited-state dipole moments are larger than their ground-state counterparts, indicating a substantial redistribution of the electron densities in a more dipolar excited state for both coumarins investigated.
“…Irrespective of the dye structure, the treated viscose fabrics were anti‐bacterial because of the anti‐bacterial activity of the dyes, and increasing the dye concentration from 1.0% to 1.9% increased the bacterial inhibition zone.Moreover, all the treated fabrics blocked UV radiation, but increasing the dye concentration resulted in an increase in the UV protecting Fibre rating. Independent of the dye concentration, the variations in both of these properties may be associated with the dye nature, that is, the chemical structure, steric hindrance, molecular geometry, location and aggregation, transmission/absorption attributes, and the coverage over the fibre/fabric …”
Section: Applicationsmentioning
confidence: 99%
“…Independent of the dye concentration, the variations in both of these properties may be associated with the dye nature, that is, the chemical structure, steric hindrance, molecular geometry, location and aggregation, transmission/absorption attributes, and the coverage over the fibre/fabric. 92,93 The dyeing and finishing of cotton fabrics demonstrated the impact of the dye structure and concentration on the extent of resin finishing (Scheme 15). Regardless of the dye structure, increasing the dye concentration from 1.0% to 1.9% resulted in the following: (i) an increase in the percentage of nitrogen, which is a direct consequence of the presence of nitrogen in the dye structure within the cellulose structure; (ii) a slight increase in the tinctorial strength, a remarkable increase in K/S along the sides of the fabric, and a slight decrease in wrinkle-recovery ability, which can be associated with the accompanying increase in the finishing bath viscosity, which prevented the diffusion of the dimethylol dihydroxy ethylene urea crosslinking agent inside the fabric structure; and (iii) variations in the K/S of treated fabrics, which are determined by the dye functionality, compatibility with other ingredients, molecular size, reactivity, affinity, and mode of interaction.…”
Sulphonamide motifs are widely found in many drug candidates with relevant biological activity. Moreover, sulphonamide azo dyes are interesting candidates for synthetic chemists because such dyes provide access to a broad range of functional group transformations. Therefore, many synthetic procedures for the preparation of sulphonamide azo dyes have been developed in recent decades, and the search for rapid and efficient protocols is ongoing. The current article aims to review recent trends in the synthesis of sulphonamide azo dyes and their applications as high‐performance colorants with antimicrobial activity. For convenience, the diverse uses of sulphonamide azo dyes are discussed from the perspective of the application type rather than the structural class.
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