Sugunan, S; Thomas, B(American Chemical Society, 1995)
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Abstract:
The Setschenow parameter and thermodynamic parameters of transfer of 2- and 4-aminobenzoic acids
from water to salt solutions have been reported. The results are discussed in terms of the structure- breaking
effects of the ions of the salts, the localized hydrolysis model, and the internal pressure theory.
Sankara Raman, S; Nampoori, V P N; Vallabhan, C P G; Ambadas, G; Sugunan, S(American Institute of Physics, 1995)
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Abstract:
The thermal diffusivity of y-alumina is determined by the photoacoustic method. The method is
calibrated by determining the thermal diffusivity of copper and aluminum. The effect of the
chemisorbed hydroxyl groups or thermal diffusivity is studied by degassing the sample at different
temperatures.
Sugunan, S; Benny, Thomas(Indian Journal of Chemistry, February , 1995)
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Abstract:
The Setschenow parameter and thermodynamic
parameters of transfer of 2- and 4- hydroxybenzoic acids
from water to salt solutions have been reported. The data
have been rationalised by considering the structure
breaking effects of the ions of the salts, the localized
hydrolysis model, the internal pressure theory and the
theory of water structure due to Symons.
Sugunan, S; Jalaja, J M(Indian Journal of Chemistry, March , 1995)
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Abstract:
The electron donating properties of Ce02 and its mixed
oxides with alumina have been determined from the studies
of adsorption of electron acceptors of various electron
affinities on the surface of these oxides. The catalytic
activity of these oxides towards some reactions such as
oxidation of alcohols and reduction of ketones have been
Correlated with their surface electrondonor properties. The
surface acidity/basicity of these oxides have also been
determined by titration method using a set of Hammett
indicators.
Sugunan, S; Devika Rani, G; Unnikrishnan, P A(Indian Journal of Engineering & Materials Sciences, October , 1995)
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Abstract:
Acid/base strength distribution of Y2O3 and its mixed
oxides with alumina catalysts are measured on Hammett
acidity function scale and expressed in terms of H0max
value. Basicity of Y2O3 increases with increase in activation
temperature and for mixed oxides the basicity increases
with increase in concentration of Y2O3, in the catalyst.
Sugunan, S; Chemparathy, G V; Anto, Paul(Indian Journal of Engineering & Materials Sciences, 1996)
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Abstract:
The surface acidity and basicity of binary oxides of Zr with Ce and La are determined using a series of Hammet indicators and Ho,,max values are reported. The generation of new acid sites habe been ascribed to the charge imbalance of M1-O-M2 bonds, where M1 and M2 are metal atoms. Both Bronsted and Lewis acid sites contribute to the acidity of the oxides
The electron donating properties, surface acidity/basicity and catalytic activity of lanthana for various dopant concentrations of strontium are reported at two activation temperatures. The catalytic activity has been correlated with electron donating properties and surface acidity/basicity of the oxide.
Sugunan, S; Ampili, S; Bindhu, Jacob; Rani, Varghese(Indian Journal of Chemistry, February , 1996)
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Abstract:
The surface acidity and basicity of ternary oxides of
La, Ce and AI have been determined using a set of
Hammett indicators. The data have been correlated
with the catalytic activity of these oxides towards the
liquid phase reduction of cycIohexanone in 2-propanol.
Mohammed Yusuff, K K; Mayadevi, S(Taylor & Francis, 1997)
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Abstract:
Some new transition metal complexes of the Schiff base
quinoxaline-2-car boxalidene-2-aminophenol (HQAP) have been
synthesized and characterized by elemental analyses, conductance
and magnetic measurements and IR and UV-Visible spectral studies.
The complexes have the following empirical formulae: [Mn(QAP121,
[Fe(QAPl2C1I, [Co(QAPl21, [Ni(QAP121 and [Cu(QAP121. A tetrahedral
structure has been assigned for the manganese(=), cobalt(II1,
nickel(II1 and copper(II1 complexes. For the iron(IIIl complex an
octahedral dimeric structure has been suggested
Surface acidity/Basicity of mixed oxides of La and Zn activated at three different temperatures were determined. The data have been correlated with the catalytic activity for liquid phase reduction of cyclohexanone in isopropanol.
Sugunan, S; Anto, Paul(Indian Journal of Chemistry, April , 1997)
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Abstract:
The surface acidity/basicity of binary oxides of Zr and La and the ternary oxides of Zr, La and Al are
reported. The data have been correlated with their catalytic activity towards liquid phase reduction of
cyclohexanone.
Sugunan, S; Bindhu, Jacob(Indian Journal of Engineering & Materials Sciences, June , 1997)
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Abstract:
The surface acidity and basicity of ternary oxides of
AI, Ce and Dy have been determined using a set of
Hammett indicators. The data have been correlated
with the catalytic activity of these oxides towards the
liquid phase reduction of cyclohexanone in 2-propanol.
The reaction is favoured by the higher basicity of
the ternary oxide.
Sugunan, S; Bindhu, J; Disha; Jessey, V(Indian Journal of Chemistry, July , 1997)
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Abstract:
The Lewis acidity of yttrium and dysprosium exchanged
zeolite Y and ZSM-5 has been determined by titration method
using Hammett indicators. The acidity of the Y form increases
with increase in concentration of the rare earth cation in the Y
zeolite. It is independent of the amount of the rare earth ion for
ZSM-5. The data have been correlated with the activity of these
zeolites for the esterification of butanol using acetic acid.
Sugunan, S; Anto, Paul(Indian Journal of Chemistry, December , 1997)
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Abstract:
The surface acidity and basicity of mixed oxides of Zr and Y
and their mixed oxides have been determined by titration method
using Hammett indicators. The acid base properties are evaluated
on a common scale of acid strength. Liquid phase reduction of
cyclohexanone has been selected as a model reaction to correlate
catalytic activity.
Sugunan, S; Kumaree Seena, C R(Indian Journal of Chemistry, May , 1998)
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Abstract:
We have investigated the changes in surface acidity/basicity
and catalytic pro~erties of samarium oxide due to surface modification
by SO42- ion. The acidity/basicity of the catalysts is
determined by titration method using Hammett indicators.
Esterification of acetic acid by n-butanol is chosen as a test
reaction. Sm203, owing to its high basicity and low acidity, does
not catalyze the reaction. But sulphated Sm20J catalyzes the
esterification reaction effectively. Activation temperature does
not have much effect on the acidity of sulphated samaria.
Sugunan, S; Kumaree Seena, C R(Indian Journal of Chemistry, August , 1998)
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Abstract:
The surface electron donor properties of sulphate modified stannic oxide have been determined from the
adsorption of electron acceptors of various electron affinities on the oxide surface. The acid base properties of
stannic oxide have been determined by titration method using Hammett indicators. Catalytic activities of the
oxide for esterification of acetic acid using n-butanol.reduction of cyclohexanone in 2-propanol and oxidation of
cyclohexanol with benzophenone have been studied. The data have been correlated with the surface electron
donor properties of these oxides. The activity for reduction and oxidation decreases and that for esterification
reaction increases on modification with sulphate ion. It has heen found that electron donating capacity decreased
when stannic oxide was modified with sulphate ion.
Description:
Note:Indian Journal of Chemistry
Vol. 37A, August 1998, pp. 669 - 673
Sugunan, S; Binsy, Varghese(Indian Journal of Chemistry, September , 1998)
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Abstract:
The electron donating properties, surface acidity/ basicity and catalytic activity of cerium - zirconium mixed
oxides at various compositions have been reported at an activation temperature of 500 degree C. The catalytic activity
for the esterification of acetic acid with n-butanol has heen correlated with electron donating properties and
surface acidity/basicity of the oxides.