http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/1616 2013-05-24T12:07:55Z 2013-05-24T12:07:55Z Rekha r mallia Dr. Prathapan, S http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/3017 2012-10-03T20:30:15Z 2007-12-01T00:00:00Z

Studies on the Solvent Dependence in the Reaction of a Few (Anthracen-9-yl)MethyLamines and Sulfanes with Reactive Acetylenes Rekha r mallia; Dr. Prathapan, S The thesis entitled ‘Studies on the Solvent Dependence in the Reaction of a Few (Anthracen-9-yl)methylamines and Sulfanes with Reactive Acetylenes’ is divided into six chapters. ln Chapter l a general survey of electron transfer reactions, Diels-Alder reactions and Michael-type additions is presented. A detailed discussion on the synthesis of several (anthracen-9-yl)methylamines is presented in Chapter 2. In Chapter 3, results of preliminary photophysical studies on a few (anthracen-9yl) methylamines are compiled. A detailed discussion on extensive examination of dependence in the reaction of (anthracen-9-yl)methylamines with reactive acetylenes is presented Chapter 4. Details on the synthesis and reaction of a few (anthracen-9-yl)methylsulfanes with DMAD are described in Chapter 5.

2007-12-01T00:00:00Z Manoj, E Dr. Prathapachandra Kurup, M.R http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/3016 2012-11-09T09:51:01Z 2007-10-01T00:00:00Z

Self-assembled Transition Metal Coordination Frameworks of Carbohydrazone and Thiocarbohydrazone Ligands: Structural, Spectral, Magnetic and Anticancer Properties Manoj, E; Dr. Prathapachandra Kurup, M.R Chemistry occupies a unique middle position in the scientific arena, between physics and mathematics on the one side and biology, ecology, sociology and economics on the other [1]. Chemistry is the science of matter and of its transformations, and life is its highest expression [2]. According to reductionist thinking biology is reducible into chemistry, chemistry into physics, and ultimately physics into mathematics. Reductionism implies the ease of understanding one level in terms of another.The work presented this thesis comprises synthesis and characterization of suitably substituted thiocarbohydrazone and carbohydrazone ligand building blocks, self-assembled metallosupramolecular square grid complexes as well as some di/multinuclear complexes. The primary aim was the deliberate syntheses of some novel transition metal framework complexes, mainly metallosupramolecular coordination square grids by self-assembly and their physico-chemical characterization. The work presented, however, also include synthesis and characterization of four mononuclear Ni(II) complexes of two thiosemicarbazones, which we carried out as a preliminary and supporting study. Based on the present work we would like to conclude that the carbohydrazones, thiocarbohydrazones and their coordination framework complexes of transition metals are promising systems for wide application in science and technology varied from physics to biotechnology. Novel classes of materials and biologically important potential compounds open up further scope of researches and we hopefully welcome any sort of related research to make this work more valuable.

2007-10-01T00:00:00Z Ambily Mary, Jacob Dr. Prathapan, S http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/3008 2012-09-02T19:10:28Z 2008-03-01T00:00:00Z

Synthesis and Photochemistry of a few Olefin appended Dibenzobarrelenes and Bisdibenzobarrelenes Ambily Mary, Jacob; Dr. Prathapan, S The thesis entitled: ‘Synthesis and Photochemistry of a few Olefin appended Dibenzobarrelenes and Bisdibenzobarrelenes’ is divided into 5 chapters.In Chapter 1, the fundamental concepts of Diels-Alder reaction, di-r:methane rearrangement and energy transfer process in organic photochemistry is discussed.Chapter 2 presents the synthesis of 9-olefin appended anthracenes and bisanthracenes. The target of synthesising various bridgehead olefin appended dibenzobarrelenes and some novel bisdibenzobarrelenes, led us to the synthesis of the appropriate alkenylanthracenes and bisanthracenes as precursor molecules. Diels-Alder reaction was the synthetic tool for the preparation of the target olefin appended dibenzobarrelenes and bisdibenzobarrelenes. This chapter attempts to throw light on our endeavours in synthesising the various 9-alkenylanthracenes and bisanthracenes.Chapter 3 deals with the synthesis of olefin appended dibenzobarrelenes and bisdibenzobarrelenes. Ever since the discovery of di-It-methane rearrangement dibenzobarrelenes, tailored with dijferent substituents at various positions have always been a tool to photochemists in unravelling the mechanisms of light induced reactions. Our intention of analysing the role of a It-moiety at the bridgehead position of the dibenzobarrelene, was synthetically envisaged via the Diels-Alder reaction. Bisdibenzobarrelenes were synthesised through tandem Diels-Alder reaction. Various alkenylanthracenes and bisanthracenes were employed as dienes and the dienophiles used were dimethyl acetylenedicarboxylate and dibenzoylacetylene. In this chapter, we report our venture in synthesising the various olefin appended dibenzobarrelenes and bisdibenzobarrelenes. Chapter 4 describes the preliminary time-resolved fluorescence studies of some olefin appended dibenzobarrelenes and bisdibenzobarrelenes.To understand the primary and secondary physicochemical processes in a photochemical reaction it is necessary to characterise the excited states and the transient intermediates during their short lifetime. A number of methods developed on the basis of the physical properties of the transient species are available for their detection. Time-correlated single-photon counting technique has been utilised in the present study of the excited states of olefin appended dibenzobarrelenes and bisdibenzobarrelenes. To understand the primary and secondary physicochemical processes in a photochemical reaction it is necessary to characterise the excited states and the transient intermediates during their short lifetime. A number of methods developed on the basis of the physical properties of the transient species are available for their detection. Time-correlated single-photon counting technique has been utilised in the present study of the excited states of olefin appended dibenzobarrelenes and bisdibenzobarrelenes.Chapter 5 portrays the photochemistry of olefin appended dibenzobarrelenes and bisdibenzobarrelenes. Dibenzocyclooctatetraene and dibenzosemibullvalene are the photoproducts obtained respectively through the singlet excited state and the triplet excited state of dibenzobarrelenes. Chemical literature shows evidences of the photoreactivity of dibenzobarrelenes generating both the singlet and triplet mediated photoproducts, in a single photoreaction. Our research target in synthesising various bridgehead olefin appended dibenzobarrelenes and bisdibenzobarrelenes, was based on the perception that olefins are eflicient triplet quenchers, thereby quenching intramolecularly the triplet excited state of the barrelenes. A It-moiety at the bridgehead position of the dibenzobarrelene, creates a tetra tr-methane system, which similar to a 6li—7l' or tri-tr-methane systems, could be the fertile ground for interesting photochemical rearrangements. Our attempts in deciphering the photochemistry of the olefin appended dibenzobarrelenes and bisdibenzobarrelenes is the substance of this chapter. Department of Applied Chemistry, Cochin University of Science and Technology

2008-03-01T00:00:00Z Annu Anna, Varghese Dr. Mohammed Yusuff, K K http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/3007 2012-09-01T20:30:10Z 2008-12-01T00:00:00Z

Zeolite encapsulated complexes of ruthenium: synthesis, characterisation and catalytic activity studies Annu Anna, Varghese; Dr. Mohammed Yusuff, K K The work presented in this thesis is mainly centered on the synthesis and characterization of some encapsulated transition metal complexes and the catalytic activity of the synthesized complexes in certain organic reactions.thesis deals with the catalytic activity of ruthenium-exchanged zeolite and the zeolite encapsulated complexes of SSC, SOD, SPD, AA, ABA, DMG, PCO, PCP, CPO and CPP in the hydroxylation of phenol using hydrogen peroxide. The products were analyzed with a GC to determine the percentage conversion and the chromatograms indicate the presence of different products like hydroquinone, catechol,benzoquinone, benzophenone etc. The major product formed is hydroquinone. From the screening studies, RuYSSC was found to be the most effective catalyst for phenol hydroxylation with 94.4% conversion and 76% hydroquinone selectivity. The influence of different factors like reaction time, temperature, amount of catalyst, effect of various solvents and oxidant to substrate ratio in the catalytic activity were studied in order to find out the optimum conditions for the hydroxylation reaction. The influence of time on the percentage conversion of phenol was studied by conducting the reactions for different durations varying from one hour to four hours. There is an induction period for all the complexes and the length of the induction period depends on the nature of the active components. Though the conversion of phenol and selectivity for hydroquinone. increases with time, the amount of benzoquinone formed decreases with time. This is probably due to the decomposition of benzoquinone formed during the initial stages of the reaction into other degradation products like benzophenones. The effect of temperature was studied by carrying out the reaction at three different temperatures, 30°C, 50°C and 70°C. Reactions carried at temperatures higher than 70°C result either in the decomposition of the products or in the formation of tarry products. Activity increased with increase in the amount of the catalyst up to a certain level. However further increase in the weight of the catalyst did not have any noticeable effect on the percentage conversion. The catalytic studies indicate that the oxidation reaction increases with increase in the volume of hydrogen peroxide till a certain volume. But further increase in the volume of H202 is detrimental as some dark mass is obtained after four hours of reaction. The catalytic activity is largely dependent on the nature of the solvent and maximum percentage conversion occurred when the solvent used is water. The intactness of the complexes within the zeolite cages enhances their possibility of recycling and the activities of the recycled catalysts show only a slight decrease when compared to the fresh samples . Department of Applied Chemistry, Cochin University of Science and Technology

2008-12-01T00:00:00Z