A study of the medium effect of mixed solvents; The benzene-acetonitrile system

1986 ◽  
Vol 51 (10) ◽  
pp. 2071-2076 ◽  
Author(s):  
Taťjana Nevěčná ◽  
Jitka Vymětalová ◽  
Vojtěch Bekárek
Keyword(s):  
Refractive Index ◽  
Spectral Data ◽  
Rate Constants ◽  
Relative Permittivity ◽  
Mixed Solvents ◽  
Ethyl Iodide ◽  
Medium Effect ◽  
Wavelength Band ◽  
Wave Numbers ◽  
The Media

Rate constants of the reaction of triethylamine with ethyl iodide (at 293.15, 313.15, 323.15, and 333.15 K) and wave numbers of the longest wavelength band maxima of 4-nitroso-N,N-dimethylaniline, 3-nitro-N,N-dimethylaniline, and 2,6-diphenyl-4-(2,4,6-triphenyl-1-pyridinio)phenoxide were measured in benzene, acetonitrile, and their eleven mixtures. Activation characteristics of the reaction of triethylamine with ethyl iodide in these media were calculated, and the correlations of rate constants and spectral data with the functions of relative permittivity and refractive index of the media used and mutually with each other were carried out.

A study of the medium effect of mixed solvents; The cyclohexane-nitrobenzene system

1986 ◽  
Vol 51 (9) ◽  
pp. 1942-1947 ◽  
Author(s):  
Taťjana Nevěčná ◽  
Vojtěch Bekárek
Keyword(s):  
Refractive Index ◽  
Spectral Data ◽  
Rate Constants ◽  
Relative Permittivity ◽  
Mixed Solvents ◽  
Ethyl Iodide ◽  
Medium Effect ◽  
Wavelength Band ◽  
The Media

Rate constants of the reaction of triethylamine with ethyl iodide (at 293.15, 313.15, 323.15, and 333.45 K) and wavenumbers of the longest wavelength band maxima of 4-nitroso-N,N-dimethylaniline and 2,6-diphenyl-4-(2,4,6-triphenyl-1-pyridinio)phenoxide were measured in nitrobenzene and thirteen mixtures of nitrobenzene with cyclohexane. The activation characteristics of the reaction of triethylamine with ethyl iodide in these media were calculated, and the correlations of rate constants and spectral data were carried out with functions of relative permittivity and refractive index of the media used and mutually with each other.

A study of the medium effect of mixed solvents; The cyclohexane-acetone system

1985 ◽  
Vol 50 (9) ◽  
pp. 1928-1934 ◽  
Author(s):  
Vojtěch Bekárek ◽  
Taťjana Nevěčná
Keyword(s):  
Refractive Index ◽  
Rate Constants ◽  
Relative Permittivity ◽  
Mixed Solvents ◽  
Valence Vibration ◽  
Dimethyl Sulphoxide ◽  
Ethyl Iodide ◽  
Medium Effect ◽  
Wavelength Band ◽  
Acetone System

Wavenumbers of the S-O bond valence vibration of dimethyl sulphoxide, wavenumbers of the longest wavelength band maxima of 3-nitro-N,N-dimethylaniline and 2,6-diphenyl-4-(2,4,6-triphenyl-1-pyridinio)phenoxide and rate constants of the reaction of triethylamine with ethyl iodide measured in mixtures of cyclohexane and acetone were correlated with functions of relative permittivity and refractive index of these media and mutually with each other.

Significance test of refractive index of solvent in evaluation of effect of medium on rates of quaternization reactions of methyl iodide with amines

1990 ◽  
Vol 55 (1) ◽  
pp. 180-184 ◽  
Author(s):  
Taťjana Nevěčná ◽  
Vojtěch Bekárek
Keyword(s):  
Refractive Index ◽  
Methyl Iodide ◽  
Rate Constants ◽  
Relative Permittivity ◽  
Significant Contribution ◽  
Activation Enthalpy ◽  
Dipole Moments ◽  
Significance Test ◽  
Activation Entropy ◽  
Aprotic Solvents

The rate constants have been measured of the reactions of methyl iodide with triethylamine (I) and tributylamine (III) at 293 K in twelve aprotic solvents, methyl iodide with tripropylamine (II) at 293, 313, 323, and 333 K in fifteen solvents differing greatly in their dipole moments, relative permittivities, and refractive indexes, and diiodomethane with tripropylamine in diiodomethane at 293 K (k1 = 2.1 10-5 s-1). The aprotic solvents predominantly affect the activation entropy which for the reaction of II varies from -200 J mol-1 s-1 (in cyclohexane) to -108 J mol-1 s-1 (in diiodomethane). The activation enthalpy of the reaction of methyl iodide with tripropylamine (II) is only little affected by aprotic solvents, a significant increase in activation enthalpy has been observed in the case of amphiprotic solvents. The evaluation of effect of medium on the rate constants of the above-mentioned reactions by means of the Kirkwood functions of relative permittivity and refractive index has shown a significant contribution of the refractive index of solvent which is comparable with the effect of relative permittivity.

A contribution to evaluation of influence of medium in electronic and infrared spectroscopy

1982 ◽  
Vol 47 (4) ◽  
pp. 1060-1068 ◽  
Author(s):  
Vojtěch Bekárek ◽  
Jan Juřina
Keyword(s):  
Refractive Index ◽  
Infrared Spectroscopy ◽  
Correlation Coefficient ◽  
Solvent Effects ◽  
Electronic Spectra ◽  
Relative Permittivity ◽  
Solvent Parameters

Dependence of ET(30) of solvent parameters on relative permittivity (ε) and refractive index (n) of solvent has been found for forty solvents in the form ET(30)=29.87 + 72.03 (ε - 1/(2ε + 1)-29.16(ε - 1) (n 2 - 1)/(2ε + 1) (2n2 + 1), the correlation coefficient being 0.958. Relation has been discussed between ET(30) and π solvent parameters and significance of the term (ε - 1). (n2 - 1)/(2ε + 1) (2n2 + 1) has been tested for evaluation of solvent effects in electronic spectra.>

Kinetic study of hydrolysis of benzoates. part xxvii. ortho substituent effect in alkaline hydrolysis of phenyl esters of substituted benzoic acids in aqueous Bu4NBr

2009 ◽  
Vol 74 (1) ◽  
pp. 29-42 ◽  
Author(s):  
Vilve Nummert ◽  
Mare Piirsalu ◽  
Signe Vahur ◽  
Oksana Travnikova ◽  
Ilmar A. Koppel
Keyword(s):  
Alkaline Hydrolysis ◽  
Rate Constants ◽  
Pure Water ◽  
Substituent Effects ◽  
Benzoic Acids ◽  
Resonance Effects ◽  
The Media ◽  
Substituted Benzoic Acids ◽  
Hydrolysis Of ◽  
Ortho Substituent

The second-order rate constants k (in dm3 mol–1 s–1) for alkaline hydrolysis of phenyl esters of meta-, para- and ortho-substituted benzoic acids, X-C6H4CO2C6H5, have been measured spectrophotometrically in aqueous 0.5 and 2.25 M Bu4NBr at 25 °C. The substituent effects for para and meta derivatives were described using the Hammett relationship. For the ortho derivatives the Charton equation was used. For ortho-substituted esters two steric scales were involved: the EsB and the Charton steric (υ) constants. When going from pure water to aqueous 0.5 and 2.25 M Bu4NBr, the meta and para polar effects, the ortho inductive and resonance effects in alkaline hydrolysis of phenyl esters of substituted benzoic acids, became stronger nearly to the same extent as found for alkaline hydrolysis of C6H5CO2C6H4-X. The steric term of ortho-substituted esters was almost independent of the media considered. The rate constants of alkaline hydrolysis of ortho-, meta- and para-substituted phenyl benzoates (X-C6H4CO2C6H5, C6H5CO2C6H4-X) and alkyl benzoates, C6H5CO2R, in water, 0.5 and 2.25 M Bu4NBr were correlated with the corresponding IR stretching frequencies of carbonyl group, (ΔνCO)X.

Ethane-1,2-diol–2-methoxyethanol solvent system. Dependence of the relative permittivity and refractive index on the temperature and composition of the binary mixture

1991 ◽  
Vol 87 (16) ◽  
pp. 2583-2588 ◽  
Author(s):  
Gian Carlo Franchini ◽  
Andrea Marchetti ◽  
Mara Tagliazucchi ◽  
Lorenzo Tassi ◽  
Giuseppe Tosi
Keyword(s):  
Refractive Index ◽  
Binary Mixture ◽  
Relative Permittivity ◽  
Solvent System

Temperaturabhängigkeit der statischen Dielektrizitätskonstante und des optischen Brechungsindexes von Flüssigkeiten

1975 ◽  
Vol 30 (3) ◽  
pp. 287-291 ◽  
Author(s):  
I. Gryczyński ◽  
A. Kawski
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Dipole Moment ◽  
Dipole Moments ◽  
Mixed Solvents ◽  
Temperature Changes ◽  
Temperature Dependences ◽  
Solvent Shifts ◽  
Pure And Mixed Solvents ◽  
Good Agreement

A variation of the temperature changes the static dielectric constant (ε) and the refractive index (n) of solvents and, in conjunction with the measurement of solvent shifts of absorption and fluorescence maxima, allows the investigation of dipole moment changes of solutes in the excited state. For this purpose, investigations of the temperature dependences of ε and n of some pure and mixed solvents of different polarities have been made. It is found that the excited dipole moments of indole, 1,2-dimethylindole, 2,3-dimethylindole and tryptophan obtained from the shifts of the fluorescence maxima in mixed solvents at high temperatures are in good agreement with those obtained in other ways.

Relative Permittivity and Refractive Index

2003 ◽  
pp. 433-473 ◽  
Author(s):  
M.R. Moldover ◽  
K.N. Marsh ◽  
J. Barthel ◽  
R. Buchner
Keyword(s):  
Refractive Index ◽  
Relative Permittivity
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