Kamlet-Taft and Catalan Studies of Some Novel Y-Shaped Imidazole Derivatives

Jayabharathi, Jayaraman; Thanikachalam, Venugopal; Devi, Kumar Brindha; Perumal, Marimuthu Venkatesh

doi:10.1007/s10895-011-1009-x

Cited by 8 publications

(6 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Kamlet–Abboud–Taft ,− and Catalán − multiparameter equations were used in the analysis of the experimental E T (dye) values for compounds 2b – 9b in pure solvents. These approaches consider a linear correlation between the experimentally obtained spectrometric parameter, E T (dye), and several solvent parameters according to eq .…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Solvatochromism of Substituted 4-(Nitrostyryl)phenolate Dyes

et al. 2015

View full text Add to dashboard Cite

4-(Nitrostyryl)phenols 2a-9a were synthesized, and by deprotonation in solution, the solvatochromic phenolates 2b-9b were formed. Their absorption bands in the vis region of the spectra are due to π-π* electronic transitions, of an intramolecular charge-transfer nature, from the electron-donor phenolate toward the electron-acceptor nitroarene moiety. The frontier molecular orbitals and natural bond orbitals were analyzed for the protonated and deprotonated forms. The calculated geometries are in agreement with X-ray structures observed for 4a, 6a, and 8a. The HOMO-LUMO energy gaps suggest that, after their deprotonation, an increase in the electron delocalization is observed. In the protonated compounds, the HOMO is primarily localized over the phenol ring and the C═C bridge. After deprotonation, it extends toward the entire molecule, including the NO2 groups. The solvatochromism of each dye was studied in 28 organic solvents, and it was found that all compounds exhibit a reversal in solvatochromism, which is interpreted in terms of the ability of the media to stabilize their electronic ground and excited states to different extents. The Catalán multiparameter equation is used in the interpretation of the solvatochromic data, revealing that the most important contribution to the solute/solvent interaction is the hydrogen-bond donor acidity of the solvent.

show abstract

Section: Resultsmentioning

confidence: 99%

Synthesis and Solvatochromism of Substituted 4-(Nitrostyryl)phenolate Dyes

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The Catalán parameters have proved to be superior to the Kamlet–Abboud–Taft parameters in previous regressions with hybrid dyes 5 . In general, the exclusion of data points obtained in water from the regressions led to improved correlations.…”

Section: Resultsmentioning

confidence: 94%

Reverse Solvatochromism of Imine Dyes Comprised of 5‐Nitrofuran‐2‐yl or 5‐Nitrothiophen‐2‐yl as Electron Acceptor and Phenolate as Electron Donor

Melo

Nicoleti

Rezende

et al. 2018

Chemistry A European J

View full text Add to dashboard Cite

Eight compounds with phenols as electron-donating groups and 5-nitrothiophen-2-yl or 5-nitrofuran-2-yl acceptor moieties in their molecular structures were synthesized. The crystalline structures of six compounds were obtained. Their corresponding phenolate dyes were studied in 29 solvents and the data showed that in all cases a reverse solvatochromism occurred. The results are explained in terms of the ability of the medium to stabilize the electronic ground and excited states of the probes to different extents. The frontier molecular orbitals were analyzed for the protonated and deprotonated forms of the compounds. The calculated geometries are in agreement with the X-ray structures determined for the compounds and it was verified that after their deprotonation an increase in the electron delocalization occurs. Radial distribution functions were calculated for the dyes in water and n-hexane to analyze different solvation patterns resulting from the interaction of the solvents with the dyes. Data obtained by using the Catalán multiparameter equation revealed that the medium acidity is responsible for hypsochromic shifts, whereas the solvent basicity, polarizability, and dipolarity contributed to bathochromic shifts of the solvatochromic band of these dyes. Two model "hybrid cyanine" dyes were used in the design of simple experiments to demonstrate that the solvatochromic behavior of these dyes in solution can be tuned with careful consideration of the properties of the medium.

show abstract

“…Two equations are frequently employed to correlate E T (probe) with solvent descriptors, that of Kamlet et al(not given) − and that of Catalán et al, − eq . We use the latter because it separates solvent dipolarity from its polarizability.…”

Section: Resultsmentioning

confidence: 99%

Understanding Solvation: Comparison of Reichardt’s Solvatochromic Probe and Related Molecular “Core” Structures

et al. 2019

View full text Add to dashboard Cite

The compound 2,6-diphenyl-4-(2,4,6-triphenylpyridinium-1-yl)phenolate, p-RB, shows distinct colors in different solvents (solvatochromism). The compound 4-(pyridinium-1-yl)phenolate, p-CB, represents the part of p-RB which is responsible for this phenomenon. We compared the solvatochromism of both compounds and also the structurally related 2-(pyridinium-1-yl)phenolate, o-CB, and (2,4-dimethyl-6-(2,4,6-triphenyl-N-pyridinium-1-yl)phenolate, o-RB. In pure solvents, plots of the empirical solvent polarity parameter [E T (probe), kcal/mol] of the different probes correlate linearly with slopes close to unity. That is, these probes are similarly sensitive to specific and nonspecific interactions with the solvents. The solvatochromism of p-CB and o-CB was studied, for the first time, in binary mixtures of water with dimethyl sulfoxide (DMSO) and 1-propanol (1-PrOH). The dependence of E T (probe) on mixture composition was nonideal due to preferential solvation of the probe by one component of the binary solvent mixture. We treated our solvatochromic data using a solvent-exchange model that considers formation of the complex solvents [HOH•••OS(CH 3 ) 2 ] and [HOH•••O(H)-C 3 H 7 ]. The model applies satisfactorily to our data and shows the importance to solvation of hydrogen-bonding and hydrophobic interactions. The preferential solvation of (more hydrophobic) p-RB is more pronounced than that of p-CB or o-CB. The solvent complex [OH 2 •••O(H)-C 3 H 7 ] is more efficient than [OH 2 ••• OS(CH 3 ) 2 ] because of more possibilities of hydrogen bonding.

show abstract

Kamlet-Taft and Catalan Studies of Some Novel Y-Shaped Imidazole Derivatives

Cited by 8 publications

References 38 publications

Synthesis and Solvatochromism of Substituted 4-(Nitrostyryl)phenolate Dyes

Synthesis and Solvatochromism of Substituted 4-(Nitrostyryl)phenolate Dyes

Reverse Solvatochromism of Imine Dyes Comprised of 5‐Nitrofuran‐2‐yl or 5‐Nitrothiophen‐2‐yl as Electron Acceptor and Phenolate as Electron Donor

Understanding Solvation: Comparison of Reichardt’s Solvatochromic Probe and Related Molecular “Core” Structures

Contact Info

Product

Resources

About