Ramanathan,R; Dr.Sugunan, S(Cochin University of Science and Technology, December , 2006)
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Abstract:
Catalysis is a very important process from an industrial point of view since the production of most industrially important chemicals involves catalysis.Solid acid catalysts are appealing since the nature of acid sites is known and their chemical behavior in acid catalyzed reactions can be rationalized by means of existing theories and models. Mixed oxides crystallizing in spinel structure are of special interest because the spinel lattice imparts extra stability to the catalyst under various reaction conditions so that theses systems have sustained activities for longer periods. The thesis entitled" Catalysis By Ferrites And Cobaltites For The Alkylation And Oxidation Of Organic Compounds " presents the preparation ,characterization ,and activity studies of the prepared spinels were modified by incorporating other ions and by changing the stoichiometry.The prepared spinels exhibiting better catalytic activity towards the studied reactions with good product selectivity.Acid-base properties and cation distribution of the spinels were found to control the catalytic activity.
Description:
Department of Applied Chemistry,
Cochin University of Science and Technology
Rajesh Krishnan, G; Dr. Sreekumar, K(Cochin University of Science and Technology, June , 2008)
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Abstract:
The present thesis has described the development of some heterogeneous
catalysts based on polymer supported dendrimers. Attachment of dendrimers to
crosslinked polymer produced new catalysts with combined benefits of both
dendrimers and heterogeneous catalysts. These were used as heterogeneous
catalysts in selected reactions. All possible attempts were taken to avoid
halogenated and aromatic solvents and toxic reagents. In short the present work
has dealt with development of environmental friendly catalysts based on
dendrimers.
Description:
Department of Applied Chemistry, Cochin University of Science and
Technology
Maya, G; Dr.Sugunan, S(Cochin University of Science and Technology, December , 2006)
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Abstract:
The aim of catalysis research is to apply the catalyst successfully in economically
important reactions in an environmentally friendly way. The present work focuses on the
modification of structural and surface properties of ceria and ceria-zirconia catalysts by
the incorporation of transition metals. The applications of these catalysts in industrially
important reactions like ethylbenzene oxidation, alkylation of aromatics are also
investigated.Sol-gel method is effective for the preparation of transition metal modified
ceria and ceria-zirconia mixed oxide since it produces catalyst with highly dispersed
incorporated metal. Unlike that of impregnation method plugging of pores is not
prominent for sol-gel derived catalyst materials. This prevents loss of surface area on
metal modification as evident for BET surface area measurements.The powder X-ray diffraction analysis confirms the cubic structure of
transition metal modified ceria and ceria-zirconia catalysts. The thermal stability is
evident from TGA/DTA analysis. DR UV-vis spectra provide information on the
coordination environment of the incorporated metal. EPR analysis ofCr, Mn and Cu
modified ceria and a ceria-zirconia catalyst reveals the presence of different oxidation
states of incorporated metal.Temperature programmed desorption of ammonia and thermogravimetric
desorption of 2,6-dimethyl pyridine confirms the enhancement of acidity on metal incorporation. High a-methyl styrene selectivity in cumene cracking reaction implies
the presence of comparatively more number of Lewis acid sites with some amount of
Bronsted acid sites. The formation of cyclohexanone during cyclohexanol
decomposition confirms the presence of basic sites on the catalyst surface.Mn and Cr modified catalysts show better activity towards ethylbenzene
oxidation. A redox mechanism through oxometal pathway is suggested.All the catalysts were found to be active towards benzylation of toluene and
a-xylene. The selectivity towards monoalkylated products remains almost 100%. The
catalytic activity is correlated with the Lewis acidity of the prepared systems.The activity of the catalysts towards methylation of phenols depends on the
strength acid sites as well as the redox properties of the catalysts. A strong
dependence of methylation activity on the total acidity is illustrated.
Description:
Department of Applied Chemistry,
Cochin University of Science and Technology
Pearl,Augustine; Dr.Girish Kumar, K(Cochin University of Science and Technology, June , 2008)
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Abstract:
The quality of a drug is determined after establishing its authenticity by testing its purity and quality of the pure substance in the drug and its formulations.Ion selective sensors have become one of the most effective and powerful means for analytical scientists in the determination of drug substances and are playing an increasing role in pharmaceutical analysis.ISEs are cost effective,easy to prepare and can be rapidly manipulated . Potentiometric ion selective sensors have been developed for six drugs namely trimethoprim, ketoconazole, lamivudine, domperidon, nimesulide and Lomefloxacin. The sensors fabricated include both PVC membrane sensor as well as carbon paste sensor. A total of sixteen different sensors have been developed. The response parameters of all the sensors have been studied and the sensors were applied to the determination of the drugs in pharmaceutical formulations and also in real samples like urine.
Description:
Department of Applied Chemistry,Cochin University of Science and Technology
Bessy Raj, B N; Dr.Prathapachandra Kurup,M R(Cochin University of Science and Technology, February , 2009)
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Abstract:
The present work deals with the complexation of Schiff
bases of aroylhydrazines with various transition metal ions. The hydrazone
systems selected for study have long 7I:-delocalized chain in the ligand molecule
itself, which get intensified due to metal-to-ligand or ligand-to-metal charge
transfer excitations upon coordination. Complexation with metal ions like copper,
nickel, cobalt, manganese, iron, zinc and cadmium are tried. Various spectral
techniques are employed for characterization. The structures of some complexes
have been well established by single crystal X-ray diffraction studies. The nonIinaer
optical studies of the ligands and complexes synthesized have been studied
by hyper-Rayleigh scattering technique.The work is presented in seven chapters and the last one deals with
summary and conclusion. One of the hydrazone system selected for study proved
that it could give rise to polymeric metal complexes. Some of the copper, nickel,
zinc and cadmium complexes showed non-linear optical activity. The NLO
studies of manganese and iron showed negative result, may be due to the inversion
centre of symmetry within the molecular lattice.
Description:
Department of Applied Chemistry,
Cochin University of Science and Technology
Binitha, N N; Dr.Sugunan, S(Cochin University of Science and Technology, October , 2006)
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Abstract:
Green chemistry boots eco-friendly,natural clays as catalysts in the chemical as well as in the pharmaceutical industry.Industry demands thermal stability,mechanical strength etc for the catalyst and there the modification methods becomes important.Pillaring tunes clays as efficient catalytic templates for shape selective organic synthesis.Here pillared clays are used as promising alternatives for the environmentally hazardous homogeneous catalysts in some industrially important Friedel-Crafts alkylation reactions of arenes with lower alchohols and higher olefins.The layer structure is enhanced upon pillaring and allows the nanocomposite formation with polyaniline to develop today’s nanoscale diameter devices.Present work gives an entry of pillared clays to the world of conducting composite nanofibers.
Description:
Department of Applied Chemistry,
Cochin University of Science and Technology
Nancy, Mathew; Dr.Prathapachandra Kurup,M R(Cochin University of Science and Technology, June , 2011)
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Abstract:
Studies on transition metal complexes have achieved a great interest due to their versatile applications.The convenient route for synthesis,the nature of ligands and stability of metal complexes has significant contributions in their applications in medicine,biology,catalysis and photonics.The present work deals wth the synthesis and characterization of metal complexes of some tridentate acylhydrazones .Hydrazones are promising ligands in coordination chemistry with interesting binding modes and applications.The acylhydrazones chosen for the current study are capable of forming complexes in different forms through tautomerism.
Description:
Department of Applied Chemistry,Cochin University of Science and Technology
Rajesh, K M; Dr.Sugunan, S(Cochin University of Science and Technology, May , 2011)
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Abstract:
The present work aims to prepare visible light responsive anion doped titania via sol-gel precipitation method.The prepared catalysts were characterized by various techniques.The photocatalytic abilities of the prepared catalysts were measured by the degradation of dyes,pesticides,hydrogen production through water splitting reaction and antibacterial study.We also compared the activities of prepared catalysts with pure titania prepared in the laboratory and one of the commercial anatase titania samples.
Description:
Dept.of Applied Chemistry,Cochin University of Science and Technology
Pearly Sebastian, Chittilappilly; Mohammed Yusuff, K K(Cochin University of Science and Technology, March , 2007)
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Abstract:
In the present study an attempt has been made to synthesize some simple complexes of
multidentate ligands. Analogous zeolite encapsulated complexes were also synthesized and
characterized. Immobilization on to polymer supports through covalent attachment is
expected to solve the problem of decomposition of many complexes during catalytic reaction.
Hence the work is also extended to the synthesis and characterization of some polymer
supported complexes of Schiff base Iigands. All the three types of synthesized complexes,
simple, zeolite encapsulated and polystyrene anchored, were subjected to catalytic activity
study towards catechol-oxidation reaction. A selected group of complexes were also screened
for their catalytic activity towards phenol-oxidation reaction. Biological screening of the
synthesized ligands and neat complexes were done with a view to establish the effect of
complexation on biological systems.
Description:
Department of Applied Chemistry,
Cochin University of Science and Technology
Kochurani, George; Dr.Sugunan, S; Dr.Mohanan, P V(Cochin University of Science and Technology, December , 2006)
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Abstract:
The prime intension of the present work was a synthetic investigation of the
preparation, surface properties and catalytic activity of some transition metal
substituted copper chromite catalysts. Homogeneous co-precipitation method is
employed for the preparation of catalysts. Since the knowledge about the structure and
composition of the surface is critical in explaining the reactivity and selectivity of a
solid catalyst. a systematic investigation of the physico-chemical properties of the
prepared systems was carried out. The catalytic activity of these systems has also been
measured in several oxidation reactions of industrial as well as environmental
relevance. The thesis is dedicated to several aspects of chromite spinels giving
emphasis to its preparation, characterization and catalytic performance towards
oxidation reactions.
Description:
Department of Applied Chemistry,
Cochin University of Science and Technology
Suja, Krishnan; Dr.Prathapachandra Kurup,M R(Cochin University of Science and Technology, June , 2008)
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Abstract:
Coordination chemistry of pentadentate 2,6-diacetylpyridine
bis(thiosemicarbazone) Schiff base ligands has been intensively studied due to the versatility of the molecular chain in order to obtain very different
geometries as well as their broad therapeutic activity. Metal complexes of
thiosemicarbazone with aldehydes and ketones have been widely reported.
But there have been fewer reports on potential pentadentate
bis(thiosemicarbazones) formed from 2,6-diacetylpyridine. Keeping these in
view, we have synthesized four bis(thiosemicarbazone) systems with
2,6-diacetylpyridine. In the present work, the chelating behavior of
bis(thiosemicarbazones) are studied, with the aim of investigating the
influence of coordination exerts on their conformation and or configuration, in
connection with the nature of the metal and of the counter ion. The selection
of the 2,6-diacetylpyridine as the ketonic part was based on its capability to
form polynuclear complexes with different coordination number. The doubled
armed bis(thiosemicarbazones) can coordinate to a metal centre as dianionic
ligand by losing its amide protons or it can coordinate as monoanionic ligand
by losing its amide proton from one of the thiosemicarbazone moiety or it can
also be coordinate as neutral ligand. Hence it is interesting to explore the
coordinating capabilities of these ligands whether in neutral form or anionic
form and to study the structural variations occurring in the ligands during
complexation such as change in conformation.
Description:
Department of Applied Chemistry,
Cochin university of Science and Technology
Laly, K; Dr.Prathapachandra Kurup,M R(Cochin University of Science and Technology, July , 2011)
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Abstract:
In the present work,the chelating behaviour of thiosemicarbazones of a heterocyclic diketone, 2,6-diacetylpyridine is studied,with the aim of investigating the influence coordination exerts on their conformation and /or configuration, in connection with the nature of the metal and of the counter ion.The various possibilities like unsubstitution,ring incorporation at terminal nitrogen and condensation of one of the ketone group alone have been tried for ligand selection.Mainly first row transition metals like manganese,iron,nickel,copper,zinc and cadmium are studied.Metals like cobalt also were studied but could not result in fruitful isolation of the compound due to solubility problems.Different spectroscopic and characterization techniques have been utilized to reveal the nature of the metal and the ligands in coordinated metal complex.
Description:
Department of Applied Chemistry,Cochin University of Science and Technology