Mathew, E J; Dr.Mohammed Yusuff,K K(Cochin University of Science & Technology, November , 1990)
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Abstract:
The thesis deals with our studies on the synthesis and
elucidation of structure of some metal complexes of dithio
ligands, such as the dithiocarbamates, xanthates and
2-aminocyclopent-1-ene-1-dithiocarboxylate and its N-alkyl
derivatives.2-Aminocyclopent-1-ene-1-dithiocarboxylate (ACDA) is an
interesting ligand, because of its potential dual capability of
bonding between the metal and the ligand. Since the earlier
reports on the complexes of ACDA contain contradictory ideas on
the nature of its bonding, it was thought worthwhile to undertake
a detailed and systematic study of these type of complexes. As
the ACDA complexes have very low solubilities in solvents like
chloroform, we have used the isopropyl derivative of ACDA as the
ligand. The increased solubility of these complexes have made it
possible to investigate their NMR and solution electronic spectra.The complexes of this ligand have not yet been reported in the
literature.We have synthesised some new mixed ligand complexes of
dithiocarbamates by reacting bis(dithiocarbamato)-µ-dichloro
dicopper complexes (obtained by the reaction of mixed benzoic
dithiocarbamic anhydride and copper(II) chloride) with ACDA or its
N-alkyl derivatives.Interactions of metal halides with the mixed anhydrides
formed from benzoylchloride and xanthates have also been
investigated. Novel complexes of the type, [Cu2(RXant)CI]
(R=i-Bu, i-Pr, n-Bu or n-Pr)) have been isolated from the reaction
of copper(II) chloride and the mixed anhydride, and these
reactions appear to be like the clock reactions reported in the
literature.It also deal with the characterisation of
the complexes of the type [Hg(R2d t c )X] (X=Cl, Br or 1),[Cu3(R2dtc)6][Cu2Br6] and [Cu(R2dtc)Cl2](R2=Me2,Et2,Pip,Morph or Pyrr)respectively, synthesised by simple and novel routes,
different from those reported earlier.
Description:
Department of Applied Chemistry, Cochin
University of Science and Technology
Vineetha,C P; Mohammed Yusuff, K K(Department of Applied Chemistry, Faculty of Science, 2002)
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Abstract:
The thesis deals with the synthesis, characterization and catalytic activity studies of some new Fe (III), Co (II), Ni (II) and Cu (II) complexes of hydrazones and their zeolite encapsulated analogues. Hydrazones have diverse applications in biological, non-biological and biochemical front. During the present study three hydrazone types of ligands namely, acetylacetone- 2-hydroxyphenylhydrazone (APAcAc), acetoacetanilide- 2-hydroxyphenylhydrazone (APAcAcA) and acetoacetanilide-3,5-dihydro-2,4-dione pyrimidylhydrazone (AUAcAcA) were synthesized by diazotization of primary amine and coupling with compounds containing active methylene group. First part of the thesis deals with the synthesis of Fe, Co, Ni and Cu complexes using three hydrazone types of ligands are given. Details regarding the characterization of these complexes with a view to establishing the molecular structures are presented in this part. The other part contains the method of encapsulation of these complexes in zeolite cavities and their characterizations of the encapsulated metal species are described. A comparitive account of the catalytic activities of the pure and encapsulated complexes for cyclohexanol oxidation was also carried out.
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
Mayadevi, S; Dr.Mohammed Yusuff,K K(Cochin University Of Science And Technology, August 6, 1997)
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Abstract:
This thesis deals with the synthesis, characterisation and
catalytic activity studies of some new transition metal complexes of the
Schiff bases, derived from quinoxaline—2—carboxaldehyde. The model
complexes derived from specially designed and synthesised Schiff bases
help us to understand the chemistry of biological systems. Schiff bases
derived from heterocyclic aldehydes like quinoxaline-2-carboxaldehyde
provide great structural diversity during complexation. The Schiff
bases synthesised in the present study ' are
quinoxaline—2—carboxa.lidene-2-aminophenol (QAP). quinoxaline—2carboxaldehyde
semicarbazone (QSC), quinoxaline-2—carboxalidene—o—
phenylenediamine (QOD) and quinoxaline-2-carboxalidene-2-furfurylamine
(QFA). The elucidation of the structure of these complexes is done
using conductance, magnetic susceptibility measurements. infrared,
UV—Vis and EPR spectral studies.
Description:
Dcpanmcm of Appiied Chemistry, Cochin Univenity of science and
Tochnology
Moosad, K P B; Dr.Nampoori,V P N(Cochin University of Science and Technology, 1988)
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Abstract:
Nonlinear optics has emerged as a new area of physics ,
following the development of various types of lasers. A number of advancements , both theoretical and experimental . have been made in the past two decades . by scientists al1 over the world. However , onl y few scientists have attempted to study the experimental aspects of nonlinear optical phenomena i n I ndian laboratories. This thesis is the report of an attempt made in this direction. The thesis contains the details of the several
investigations which the author has carried out in the past few years, on optical phase conjugation (OPC) and continuous wave CCVD second harmonic generation CSHG). OPC is a new branch of nonlinear optics, developed only in the past decade. The author has done a few experiments on low power OPC in dye molecules held in solid matrices, by making use of a degenerate four wave mixing CDFWND scheme. These samples have been characterised by studies on their absorption-spectra. fluorescence spectra. triplet lifetimes and saturation intensities. Phase conjugation efficiencies with r espect to the various parameters have been i nvesti gated . DFWM scheme was also employed i n achievi ng phase conjugation of a br oadband laser C Nd: G1ass 3 using a dye solution as the nonlinear medium.
Description:
Department of Physics, Cochin
University of Science and Technology
Vinoj, M N; Dr.Kurian, C V(Cochin University of Science and Technology, November , 2003)
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Abstract:
The discovery of the soliton is considered to be one of the most significant
events of the twentieth century. The term soliton refers to special kinds of waves
that can propagate undistorted over long distances and remain unaffected even
after collision with each other. Solitons have been studied extensively in many
fields of physics. In the context of optical fibers, solitons are not only of fundamental
interest but also have potential applications in the field of optical fiber
communications. This thesis is devoted to the theoretical study of soliton pulse
propagation through single mode optical fibers.
Description:
Department of Physics, Cochin University of Science and Technolog
Jelaja,P; Mohammed Yusuff, K K(DEPARTMENT OF APPLIED CHEMISTRY, February , 2003)
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Abstract:
In this regard Schiff base complexes have attracted wide attention. Furthermore, such complexes are found to play important role in analytical chemistry, organic synthesis, metallurgy, refining of metals, electroplating and photography. Many Schiff base complexes are reported in literature. Their properties depend on the nature of the metal ion as well as on the nature of the ligand. By altering the ligands it is possible to obtain desired electronic environment around the metal ion. Thus there is a continuing interest in the synthesis of simple and zeolite encapsulated Schiff base complexes of metal ions. Zeolites have a number of striking structural similarities to the protein portion of natural enzymes. Zeolite based catalysts are known for their remarkable ability of mimicking the chemistry of biological systems. In view of the importance of catalysts in all the areas of modern chemical industries, an effort has been made to synthesize some simple Schiff base complexes, heterogenize them by encapsulating within the supercages of zeoliteY cavities and to study their applications. The thesis deals with studies on the synthesis and characterization of some simple and zeoliteY encapsulated Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) complexes and on the catalytic activity of these complexes on some oxidation reactions. Simple complexes were prepared from the Schiff base ligands SBT derived from 2-aminobenzothiazole and salicylaldehyde and the ligand VBT derived from 2-aminobenzothiazole and vanillin (4-hydroxy-3- methoxybenzaldehyde). ZeoliteY encapsulated Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) complexes of Schiff base ligands SBT and VBT and also of 2-aminobenzothiazole were synthesized. All the prepared complexes were characterized using the physico-chemical techniques such as chemical analysis (employing AAS and CHN analyses), magnetic moment studies, conductance measurements and electronic and FTIR spectra. EPR spectra of the Cu(II) complexes were also carried out to know the probable structures and nature of Cu(II) complexes. Thermogravimetric analyses were carried out to obtain the information regarding the thermal stability of various complexes. The successful encapsulations of the complexes within the cavities of zeoliteY were ascertained by XRD, surface area and pore volume analysis. Assignments of geometries of simple and zeoliteY encapsulated complexes are given in all the cases. Both simple and zeoliteY encapsulated complexes were screened for catalytic activity towards oxidation reactions such as decomposition of hydrogen peroxide, oxidation of benzaldehyde, benzyl alcohol, 1-propanol, 2-propanol and cyclohexanol.
Xavier, K O; Dr.Mohammed Yusuff,K K(Cochin University of Science & Technology, June , 2000)
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Abstract:
Zeolite encapsulated transition metal complexes have received wide attention as an
effective heterogenized system that combines the tremendous activity of the metal
complexes and the attractive features of the zeolite structure. Zeolite encapsulated
complexes offer a bright future for attempts to replace homogeneous systems retaining
its catalytic activity and minimizing the technical problems. especially for the partial
oxidation of organic compounds. Studies on some zeolite encapsulated transition metal
complexes are presented in this thesis. The ligands selected are technically important in a
bio-mimetic or structural perspective. Attempts have been made in this study to
investigate the composition, structure and stability of encapsulated complexes using
available techniques. The catalytic activity of encapsulated complexes was evaluated for
the oxidation of some organic compounds. The recycling ability of the catalyst as a
result of the encapsulation was also studied.Our studies on Cu-Cr/Al2O3, a typical metal oxide catalyst. illustrate the use of
design techniques to modify the properties of such conventional catalysts. The catalytic
activity of this catalyst for the oxidation of carbon monoxide was measured. The effect
of additives like Ce02 or Ti02 on the activity and stability of this system was also
investigated. The additive is potent to improve the activity and stability ofthe catalyst so
as to be more effective in commercial usage.
Description:
Department of Chemical Oceanography,
Cochin University of Science
and Technology
Chitra,M R; Dr.Vijayakumar, A(Cochin University Of Science And Technology, September 2, 2013)
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Abstract:
For routing problems in interconnection networks it is important
to find the shortest containers between any two vertices,
since the w-wide diameter gives the maximum communication
delay when there are up to w−1 faulty nodes in a network modeled
by a graph. The concept of ‘wide diameter’ was introduced
by Hsu [41] to unify the concepts of diameter and The concept of ‘domination’ has attracted interest due to
its wide applications in many real world situations [38]. A connected
dominating set serves as a virtual backbone of a network
and it is a set of vertices that helps in routing.
In this thesis, we make an earnest attempt to study some
of these notions in graph products. This include, the diameter
variability, the diameter vulnerability, the component factors
and the domination criticality.connectivity
Description:
Department of Mathematics
Cochin University of Science and Technology