Department of Chemistry

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    Synthesis of Selected Ffluorocompounds of Copper(i) and Manganese(iii) and development of Peroxo-metal assisted environmentally preferable methodologies and reagents for bromination of organic substrates.
    (2001) Dhar, Siddhartha Sankar
    The results and findings of the research work being presented in this thesis are based on the following aspects of inorganic and coordination chemistry of vanadium(V), molybdenum(VI), copper(I), manganese(III) and iron(III). While the work on copper and manganese involves the synthesis and characterisation of some fluoro compounds of these two metals in the oxidation states mentioned above, the investigation on vanadium and molybdenum includes the ability of their peroxo-intermediates to generate the active bromine species Br3 - from Br-, leading to the development of novel synthetic protocols and reagents for bromination of organic substrates. The investigation on iron(III) is concerned with the role of iron(III) chloride, FeCl3 as a catalyst in the bromination by TBATB, and evidence for involvement of HBr+H in the process. The text is distributed over seven chapters.
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    Peroxovanadate (v) mediated synthesis of quaternary ammonium tribromides and oxidative organic brominations, synthesis and structural assessment of newer heteroligand diperoxovanad (v) and efficacy
    (2002) Bora, Upasana
    The thesis of above mentioned title is based on the results of a few chosen aspects of peroxovanadium(V) and oxofluorochromium(VI) chemistries. While it focuses, in part, on peroxovanadate(V) mediated synthesis of quaternary ammonium tribromides and oxidative organic brominations, a relatively smaller section of the text is dedicated to the synthesis and structural assessment of a set of newer heteroligand diperoxovanadates(V). The other part of the thesis manifests the efficacy of a new chromium(VI) reagent, especially for..
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    Synthesis characterisation and physicochemical studies of some polyphenolic compounds
    (2002) Handique, Jyotirekha G.
    Abstract not available
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    Oxidative transformations of some activated aromatic compounds mediated by cobalt (II) and copper (II) complexes
    (2002) Puzari, Amrit
    The oxidative polymerisation and hydroxylation reactions of aromatic compounds are biologically important reactions. Cobalt complexes are important for oxidative reactions from its relevance to the reactivity of vitamin B12. On the otherhand copper complexes have special interest from their role in enzymes such as Tyrosinase and Galactose oxidase etc. They also have direct relevance in biosynthesis through oxidative polymerisation to give lignin that constitutes major component of plants. The development of reagent that would cause selective transformations under mild conditions and also the biocompatibility of such reagents are the few important points for success of such reactions. The thesis embodies the results on cobalt(II) and copper(II) catalysed oxidative reactions of activated...
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    Some oxidative reactions of silanes and related compounds catalysed by copper(II) and palladium(ii) complexes
    (2003) Purkayastha, Arup
    This thesis is mainly based on silicon-oxygen bond forming reactions. Some physiochemical studies of tetrachlorocuprate complexes to establish a structure- reactivity correlation are also included. There are five chapters in the thesis. In Chapter 1 a general introduction on synthetic methodology for siloxanes, their classification and utility is given. Chapter 2 contains the synthesis and characterisation of few tetrachlorocuprates. In chapter 3 the utility of tetrachlorocuprate complexes as catalyst for the synthesis of silylether from Si-H bond activation is discussed. In Chapter 4 a few palladium(II) complexes having nitrogen donor ligands are described. The Chapter 5 gives details of the experiments with relevant spectroscopic and other analytical data of the various compounds synthesised in Chapter 2, Chapter3 and Chapter 4.
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    Peroxovanadium catalysed oxidative transformations of organic functional groups & tetrabutylammonium tribromide in organic synthesis
    (2003) Gopinath, Rangam
    This thesis consists of two chapters, chapter I is about peroxovanadium catalysed oxidative transformations of organic functional groups and chapter II deals with tetrabutylammonium tribromide in organic synthesis. Each chapter contains four sectionsdescribing the introduction, present work, experimental section and spectral details...
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    Development of newer catalytic systems and protocols for a few important catalysts and inorganic reagents based on cobalt (II and III), copper (II), chromium (VI), vanadium (IV and V) and Tribromide (Br3)
    (2004) Dehury, Sanjay K
    The present thesis is based on the results of investigation of a few chosen aspects of metal acetylacetonates, oxofluorochromates (VI), ammonium tribromides and peroxovanadates (V). It constitutes, in part, an interpretative account of solvent-less and peroxometal- mediated synthesis of metal acetetylacetonates and development of metal acetylacetonate based heterogeneous catalysts and catalytic systems to work in water. In the next part of the thesis the importance of synthesis and versatility of some chromium (VI) reagents and catalysts have been highlighted. Another part of the thesis focuses on solvent-less synthesis of quaternary ammonium tribromides and solid-phase experiments for bromine-less brominations. The concluding section presents our work on synthesis, isolation, and structural assessment of a few vanadium-peroxo-citrate complexes. The subject matter of the thesis is...
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    Spectroscopic investigations of fluid flow in soap bubbles & Au-nanoparticles and its polyaniline composite synthesis
    (2004) Sarma, Tridib Kumar
    This thesis consists of experimental investigations in the following two areas. (i)Stabilization of single soap bubbles and their spectroscopic investigation. Observation o Marangoni effect driven upwardly mobile fluid layer in a soap bubble film. Control of the fluid movement by controlling surfactant concentration gradient. (ii)Synthesis of Au-nanoparticles (NPs) from reduction of HAuCl4 by H2O2. Generation of shape- selected Au-NPs. Preparation of Au NP-conducting polyaniline (PANI) composite. Solubilization of the composite in aqueous starch solution. Colloidal polyaniline and Au-NPs-PANI composite nanoparticle synthesis.
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    Newer physical and chemical methods of generating polymer films with macroscopic, mesoscopic and nanoscopic patterns
    (2004) Chowdhury, Devasish
    The underlying theme of the experimental investigations carried out in the present thesis has been to find newer physical and chemical methods of generating polymer films with macroscopic, mesoscopic and nanoscopic patterns. First of all, a new method of formation of thin polyaniline film at the air-water interface is reported. It was observed that during polymerization of aniline coupled to iron (ferroin) catalyzed Beluosov-Zhabotinsky (BZ) reaction had resulted in the formation of thin film of polyaniline at the air-water interface, in addition to polymerization in the bulk. Also, film formation could be observed under non-BZ reaction conditions. The film consisted of macroscopic patterns that varied from film to film. However, each of these films contained mesoscopic patterns, observable under the microscope, which were characteristic of the reaction catalyst. Further, a new p....
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    Syntheses of enantiomerically pure chiral hosts using amino acid derived ligands with Fe(III), Ni(II) and Cu(II) ions
    (2004) Alam, Md. Akhtarul
    This thesis represents our attempt to synthesize enantiopure chiral cavities, with our exploration of the coordination chemistry of the amino acid derived chiral tetradentate ligands and three first row transition metal ions namely Fe(III), Ni(II) and Cu(II). In the process we have been successful in the synthesis and characterization of three chiral cavities of different size and shape, one porous 1D helical network and two structural models for metalloenzyme active sites. The thesis has been divided into seven chapters. Chapter wise summary of the work is presented below...
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    New synthetic methodologies for thio-and dethioacetalization of carbonyl compounds, and desilyation of tert-butyldimethylsilyl ethers
    (2004) Mondal, Ejabul
    This dissertation describes the successful efforts on the development of new synthetic methodologies in protection-deprotection chemistry for thio- and dethioacetalization of carbonyl compounds and desilylation of tert-butyldimethylsilyl ethers to the hydroxyl compounds.The thesis contains mainly three chapters. Each chapter is subdivided into two parts viz. Part I and Part II. In each of the Chapter, Part I describes a review of literature of the present work and its significance. Similarly, in each chapter of the Part II is subdivided into sections, which give an account of the work carried out by the candidate. Chapter I, Part I briefs the usefulness and importance of dithioacetals in organic synthesis as well as a survey of their preparations from the corresponding carbonyl compounds. In addition, it also highlights reasons for choosing the present research problem for investiga ...
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    Influence of protein aggregation and macromolecular crowing on the dynamics and function of protiens respectively
    (2005) Homchaudhuri, Lupamudra
    The phenomenon of macromolecular crowding is ubiquitous in cells. It is reported to affect equilibria and kinetics of processes taking place in cells and is also hypothesized to affect enzyme catalyzed reactions. A part of this doctoral work was directed towards ascertaining the effect of crowding on an enzyme catalyzed reaction in an environment crowded with synthetic crowding agents viz., dextran (15-500 kDa ) and Ficoll (70 and 400 kDa). The hydrolysis of p-nitrophenyl phosphate by alkaline phosphatase was used as the model reaction for the purpose.We observed that macromolecular crowding affects the catalytic rate of hydrolysis of p-nitro phenyl phosphate in a size dependent manner. In the presence of increasing concentrations of 15-70 kDa dextrans, the rates were observed to be partly transition rate limited and partly diffusion controlled. However, in the presence of the larger ...
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    Synthesis, structure and properties of a few Bis- Phenols and Diaryl Quinone Methides
    (2005) Sarma, Rupam Jyoti
    The chemistry of bis- phenols and its derivatives is one of the important aspects of synthetic organic chemistry. This subject has gained relevance because of the various applications of bis-phenols which may involve some simple molecules or complex macromolecules containing the bis-phenol framework. The work described in this thesis, “Synthesis, structure and properties of a few bis-phenols and diaryl quinone methides” details some of the important findings related to the synthesis of bis-phenols from phenol, 2,6-dimethylphenol and 2-naphthol. This thesis focusses on the structures and properties of the bis(4-hydroxy-3,5-dimethylphenyl) (aryl) methane, which hitherto has not been studied systematically. This study draws importance from another fact that this compounds can be precursors to diaryl quinone methides. With a view to define such study we introduce a brief review of the state-of –art of bis-phenols and the different aspects related to the synthesis, structure, properties and applications and their analogs in the first chapter. The supramolecular assemblies from bis-phenols are also analysed with suitable examples to illustrate the versatility of these molecules.
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    Some aspects of the oxidation of organic substrates and synthesis of stereoregular chiral polymers
    (2006) Velusamy, Subbarayan
    The thesis has four chapters. The first chapter describes the oxidation of alcohols with molecular oxygen in the presence of recyclable polyaniline supported vanadium and molybdenum catalysts. In the second chapter, the oxidation of alcohols, alkanes and sulfides is demonstrated with copper(II) salan in the presence of 30% aqueous H2O2. The third chapter focuses on the selective oxidation of primary alcohols to aldehydes and sulfides to sulfoxides by the combined use of copper(II) salan and TEMPO. Molecular oxygen and 30% aqueous H2O2 have been employed as the terminal oxidants. The final chapter describes the synthesis and application of a chiral main chain polymer with optically active (1R,2R)-1,2-diamidocyclohexane for the asymmetric desymmetrization of cyclohexene oxide..
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    Tetrabutylammonium tribromide in organic synthesis & N-Acylation in aqueous medium
    (2006) Naik, Sarala
    The contents of this thesis have been divided into two chapters summarising the results based on the experimental works performed during the complete course of the research. Each chapter constitutes four sections, sections A-D describing introduction, present work, experimental work and spectral data respectively. Tetrabutylammonium tribromide (TBATB) in organic synthesis is the theme of chapter 1 in which various synthetically useful organic functional group transformations such as thioacetalisation, transthioacetalisation of carbonyl compounds, tetrahydropyranylation and depyranlation, acylation of alcohols and direct condensation of carboxylic acids with alcohols achieved utilising the in situ acidity of TBATB has been described. With the endeavour to understand the chemoselectivity in thioacetalisation, a brief theoretical study has been performed and described in chapter 1. The second chapter of this dissertation elucidates the results pertaining to N-acylation of amines in water serving as the reaction medium.
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    Newer synthetic methodologies for tetrahydropyranylation/depyranylation, transition metal-free oxidation and thia-michael reactions
    (2006) Ghosh, Subrata
    This dissertation describes thesuccessful efforts on the development of newer synthetic methodologies for tetrahydropyranylation/depyranylation, transition metal-free oxidation and thia-Michael reactions. The thesis contains mainly three chapters. Each chapter is subdivided into twoparts viz. Part I and Part II. Part I descrives a review of literature of the present work and its significance. Similarly, Part II gives an account of the work carried out by the candidate. Chapter I, Part I elaborates the importance of tetrahydropyranyl ethers in organic synthesis and their preparations from the corresponding hydroxyl compounds as well as their cleavage into the parent hydroxyl compounds. In addition, it also highlights reasons for choosing the research problem for investigation...
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    Applications of phosphonium- and sulfonium bromide & silica supported perchloric acid for developing new synthetic methodologies
    (2006) Choudhury, Md Lokman Hakim
    This dissertation describes the successful efforts on the development of new synthetic methodologies in protection-deprotection chemistry as well as α- bromination of β-ketoesters and 1,3-diketones employing mainly three versatile reagents acetonyltriphenylphosphonium bromide (ATPB), bromodimethylsulfonium bromide (BDMS) and silica supported perchloric acid. The thesis mainly contains three chapters. Each chapter is divided into two parts viz. Part I and Part II. Part I describes a general review on the usefulness of that particular reagent in various organic transformations and a brief literature survey from the year 1990 to till to date for dealing with that particular transformation investigated. Part II of the each chapter is subdivided into two sections : Section A and Section B which will describe an account of work carried out by the candidate. Chapter I, Part I describes a brief literature review on the application of acetonyltriphenylphosphonium bromide (ATPB) in various organic transformations and a brief survey on desilylation and acetylation.
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    Some aspects of the chemistry of acylation reactions
    (2006) Bosco, J William John
    Abstract Not available
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    Newer Catalytic Methodologies for C-N, C-S Bonds Formation and Oxidation of Sulfides, Bromide and Alcohols with H2O2
    (2007) Hussain, Sahid
    Catalysis plays an important part in rendering chemical transformations very effective, highly selective and environmentally safer. catalysis is indeed not only one of the principal tenents of "" Green chemistry' but also is an integral part of it. the timely publication of a compendium on 'Green chemistry' and catalysis' by sheldon puts this point affirm beyond any scope of imagination. the invention of new, clean and appropriate catalysis for a chosen transformation is extremely important. and for this, a clear understanding of this chemistry of a prospective catalysis or a catalytic system and the transformation on which the catalysis is to be applied upon is an essential prerequisite....