Pyridinium N-phenolate betaine dyes as empirical indicators of solvent polarity: Some new findings

2004 ◽  
Vol 76 (10) ◽  
pp. 1903-1919 ◽  
Author(s):  
C. Reichardt
Keyword(s):  
Solvent Polarity ◽  
External Pressure ◽  
Solution Temperature ◽  
Cellulose Derivatives ◽  
Solvent Mixtures ◽  
Surface Polarity ◽  
Solubility In Water ◽  
Nonpolar Solvents ◽  
New Findings ◽  
Charge Transfer Absorption Band

Solutions of the zwitterionic betaine dye 4-(2,4,6-triphenylpyridinium-1-yl)-2,6-di- phenylphenolate are solvatochromic, thermochromic, piezochromic, and halochromic. That means the position of its longest-wavelength intramolecular charge-transfer absorption band depends on solvent polarity, solution temperature, external pressure, and the nature and concentration of added salts. The extraordinarily large negative solvatochromism of this standard betaine dye has been used to establish UV/vis spectroscopically an empirical scale of solvent polarity, called ET(30), respectively ETN scale, meanwhile known for many organic solvents and solvent mixtures. In this review, the solvatochromic properties of some new hydrophilic and lipophilic betaine dyes with better solubility in water (respectively, nonpolar solvents), as well as some recent applications of these betaine dyes in various fields of interest [e.g., microheterogeneous (micellar) and polymer solutions, chemical sensors, as well as surface polarity of silicas, aluminas, and cellulose derivatives] are described.

Pyridinium-N-phenolate betaine dyes as empirical indicators of solvent polarity: Some new findings

2008 ◽  
Vol 80 (7) ◽  
pp. 1415-1432 ◽  
Author(s):  
Christian Reichardt
Keyword(s):  
Sol Gel ◽  
Solvent Polarity ◽  
General Term ◽  
External Pressure ◽  
Solution Temperature ◽  
Solvent Mixtures ◽  
Practical Applications ◽  
New Findings ◽  
Organized Media ◽  
Silica Alumina

Solutions of the zwitterionic betaine dye 2,6-diphenyl-4-(2,4,6-triphenylpyridinium-1-yl)phenolate (hereinafter called standard betaine dye) and its derivatives are solvatochromic, thermochromic, piezochromic, and halochromic. That is, the position of its longest-wavelength intramolecular charge-transfer (CT) absorption band depends on solvent polarity, solution temperature, external pressure, and the type and concentration of salts (ionophores) added to the betaine dye solution. The outstanding large negative solvatochromism of this standard betaine dye has been used to establish UV/vis spectroscopically a comprehensive set of empirical parameters of solvent polarity, called ET(30) resp. ETN values, now known for many molecular and ionic solvents as well as for a great variety of solvent mixtures. This report describes relevant physicochemical properties of this standard betaine dye as well as the definition and some more recent practical applications of these solvent polarity parameters, derived from the standard betaine dye and its derivatives. In particular, the perichromism of the standard betaine dye can be used to study the polarity of microheterogeneous solutions (e.g., micelles and other organized media), surfaces (e.g., silica, alumina, cellulose), glasses (e.g., sol-gel systems), and solids (e.g., polymers), and for the construction of chemical sensors. As extension to solvatochromism, the more general term perichromism describes UV/vis band shifts of chromophore-containing solutes which are caused not only by changes in the surrounding solvent sphere, but also by their embedding in other surroundings such as micelles, vesicles, glasses, polymers, solids, interfaces, and surfaces. Some representative examples for such extended applications of the perichromic standard betaine dye are given.

Solvent effect on simple and high yield synthesis of polydichlorophosphazene precursor Cl3PNSiMe3

2021 ◽  
Author(s):  
Elif Büşra Çelebi ◽  
Ferda Hacıvelioğlu
Keyword(s):  
Solvent Effect ◽  
Room Temperature ◽  
Solvent Polarity ◽  
High Yield ◽  
Effect Of Solvent ◽  
Nonpolar Solvents

The effect of solvent polarity on the reaction of PCl5 with (Me3Si)2NH has been investigated and it is found that nonpolar solvents promote the formation of Cl3PNSiMe3, whereas the more polar chloroform gives unusual phosphazenes at room temperature.

scholarly journals High colloidal stability ZnO nanoparticles independent on solvent polarity and their application in polymer solar cells

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Woojin Lee ◽  
Jiwoo Yeop ◽  
Jungwoo Heo ◽  
Yung Jin Yoon ◽  
Song Yi Park ◽  
...  
Keyword(s):  
Solar Cells ◽  
Zno Nanoparticles ◽  
Colloidal Stability ◽  
Polymer Solar Cells ◽  
Atmospheric Condition ◽  
Solvent Polarity ◽  
Zno Nps ◽  
Long Term Stability ◽  
Nonpolar Solvents ◽  
Efficient Route

Abstract Significant aggregation between ZnO nanoparticles (ZnO NPs) dispersed in polar and nonpolar solvents hinders the formation of high quality thin film for the device application and impedes their excellent electron transporting ability. Herein a bifunctional coordination complex, titanium diisopropoxide bis(acetylacetonate) (Ti(acac)2) is employed as efficient stabilizer to improve colloidal stability of ZnO NPs. Acetylacetonate functionalized ZnO exhibited long-term stability and maintained its superior optical and electrical properties for months aging under ambient atmospheric condition. The functionalized ZnO NPs were then incorporated into polymer solar cells with conventional structure as n-type buffer layer. The devices exhibited nearly identical power conversion efficiency regardless of the use of fresh and old (2 months aged) NPs. Our approach provides a simple and efficient route to boost colloidal stability of ZnO NPs in both polar and nonpolar solvents, which could enable structure-independent intense studies for efficient organic and hybrid optoelectronic devices.

Role of solvent polarity on fluorescence quenching of 3MOCE in binary solvent mixtures

2020 ◽  
Author(s):  
S. Vaijayanthimala ◽  
Kalpana Sharma ◽  
Raveendra Melavanki ◽  
P. Bhavya ◽  
U. Meghana ◽  
...  
Keyword(s):  
Fluorescence Quenching ◽  
Solvent Polarity ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Binary Solvent Mixtures ◽  
Role Of Solvent

Pyridinium N-phenoxide betaines and their application to the determination of solvent polarities, XXIV. Syntheses and UV-vis spectroscopic properties of new lipophilic tert-butyl- and 1-adamantyl substituted, negatively solvatochromic pyridinium N-phenolate betaine dyes

1998 ◽  
Vol 76 (6) ◽  
pp. 686-694 ◽  
Author(s):  
Christian Reichardt ◽  
Stefan Löbbecke ◽  
Abdol Mohammed Mehranpour ◽  
Gerhard Schäfer
Keyword(s):  
Solvent Polarity ◽  
Spectroscopic Properties ◽  
Tert Butyl ◽  
Nonpolar Solvents ◽  
Phenyl Rings

Syntheses and negative solvatochromism of two new lipophilic pentaphenyl pyridinium N-phenolate betaine dyes, substituted with seven tert-butyl groups (9) or with three tert-butyl and two 1-adamantyl groups (13) in the peripheral phenyl rings, are described in order to get zwitterionic dyes that are more soluble in nonpolar solvents such as the standard betaine dye, 1, which has been used for the construction of an empirical scale of solvent polarity, called the ET(30) scale.Key words: betaine dyes, ET(30) values, lipophilic dyes, pyridinium N-phenolate betaine dyes, solvatochromism, solvent polarity.

The Electric Dipole Moments of Methine Dyes – Comparison of Experimental Results with Theoretical Predictions

1982 ◽  
Vol 37 (9) ◽  
pp. 1024-1026
Author(s):  
Z. Salamon ◽  
A. Skibiński ◽  
K. Celnik
Keyword(s):  
Dipole Moments ◽  
Stokes Shift ◽  
Emission Spectra ◽  
Solvent Polarity ◽  
Electronic Charge ◽  
Excited Singlet ◽  
Nonpolar Solvents ◽  
Singlet States ◽  
Theoretical Predictions ◽  
Excited Singlet States

Abstract Absorption and emission spectra of methine dyes in polar and nonpolar solvents were measured. From the Stokes shift as a function of solvent polarity the dipole moments of excited singlet states have been estimated and compared with the quantum chemical predictions. Also the π-electronic charge distribution in the ground and first excited singlet electronic states and bond orders of the dyes were calculated. All investigated methines showed an increase in dipole moment upon excitation to the first excited emitting state.

scholarly journals Probing Solvation Effects in Binary Solvent Mixtures with the Use of Solvatochromic Dyes

2021 ◽  
Author(s):  
Ioanna Deligkiozi ◽  
Raffaello Papadakis
Keyword(s):  
Preferential Solvation ◽  
Solvent Polarity ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Two Phase ◽  
Binary Solvent Mixtures ◽  
The Third ◽  
Beta Cyclodextrin ◽  
High Responsiveness ◽  
Linear Solvation

In this work three molecules exhibiting dual sensing solvatochromic behaviors are examined in the context of solvation in binary solvent mixtures (BSMs). The compounds studied involve two functional groups with high responsiveness to solvent polarity namely pentacyanoferrate(II) (PC) and azo groups. Two of these compounds are [2]rotaxanes involving alpha- or beta- cyclodextrin (CyD) and the third is their CyD-free precursor. The dual solvatochromic behavior of these compounds is investigated in water/ethlylene glycol (EG) mixtures and their dual solvatochromic responses are assessed in terms of the intensity of solvatochromism and the extent of preferential solvation. To achieve this the linear solvation model by Kamlet, Abboud and Taft [J. Organomet. Chem. 1983, 48, 2877–2887] and the two-phase model of solvation by Bagchi and coworkers [J. Phys. Chem. 1991, 95, 3311–3314] are employed. The influence of the presence or lack of CyD (alpha- or beta-) on these dual solvatochromic sensors is analyzed.

The effect of solvents on the oxidation of butyraldehyde catalysed by ferrocene

1981 ◽  
Vol 46 (1) ◽  
pp. 201-218 ◽  
Author(s):  
Jaroslav Včelák
Keyword(s):  
Oxidation Rate ◽  
Kinetic Equations ◽  
Reaction Medium ◽  
Solvent Polarity ◽  
Dielectric Constants ◽  
Effect Of Solvents ◽  
Nonpolar Solvents ◽  
Similar Dependence ◽  
Donor Ability ◽  
Solubility Of Oxygen

Oxidation of butyraldehyde to butyric acid catalysed by ferrocene in 10 solvents has been described by kinetic equations for autocatalysis. Rate constants of these equations were correlated with the properties of solvents. The oxidation rate was found to be independent of viscosity and fluidity of the reaction medium, electrophilicity expressed by ETfunction and the donor ability of solvents. Only in nonpolar solvents the oxidation rate depended on (nD)-2s. The rate of the title oxidation reaction was dependent on the polarity of reaction medium which was characterized by dipole moment and by functions of dielectric constants and increased with increasing solvent polarity. A similar dependence was also obtained with the use of solubility parameter and cohesion pressure of solvents. The rate of the oxidation increase with increasing solubility of oxygen in solvents. These dependences were used to discuss some steps of the mechanism of this oxidation.

Sign in / Sign up

Export Citation Format

Share Document