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Synthesis of Benzothiazinones Benzothiazines and Their Selenium Analogues Through Novel Synthetic Routes
Benzo fused N-heterocyclic scaffolds containing oxygen, sulphur or selenium have found wide interest in the field of drug-discovery. Among these N-heterocycles, benzothiazine, benzoxazine, benzoselenazine and benzothiazinone derivatives are a unique class of compounds and have a larger scope towards the development of efficient and simple synthetic methodologies for their synthesis with readily available substrates. newlineDuring the course of the present thesis a convenient and simple synthetic procedures were developed for the synthesis of benzothiazines, benzoxazines, benzoselenazines and benzothiazinones in an onepot methodology. 2-aryl/alkyl substituted 1,3-benzothiazines and selenazines were synthesized by reacting 2-amino benzyl alcohols and thio or seleno benzamides in the presence of T3P.A reagent controlled methodology was developed for the synthesis of 2-amino substituted 1,3-benzothiazines and oxazines. Initially, various 2-amino benzylalcohols are reacted with newlineisothiocyanates to form the corresponding thioureas. The formed thioureas undergo newlinecyclodehydration in the presence of T3P to yield 2-amino substituted 1,3-benzothiazines newlineand on the other hand molecular iodine facilitates desulfurization of the thiourea to yield 2-amino substituted 1,3-benzoxazines. 2-amino substituted 1,3-benzothiazinones were synthesized by reacting anthranilic acids and isothiocyanates in the presence of EDC.HCl. 2-aryl substituted 1,3-benzothiazinones were synthesized by employing thiobenzamides in the presence of T3P. All the compounds synthesized were characterized by 1HNMR, 13C, Mass spectroscopic (LCMS, HRMS) analysis. Docking studies against TANKYRASE-1 enzyme for colorectal cancer (CRC) and antibacterial studies were also discussed. -
Synthesis of benzothiazinones, benzothiazines and their selenium analogues through novel synthetic routes /
Benzo fused N-heterocyclic scaffolds containing oxygen, sulphur or selenium have found wide interest in the field of drug-discovery. Among these N-heterocycles, benzothiazine, benzoxazine, benzoselenazine and benzothiazinone derivatives are a unique class of compounds and have a larger scope towards the development of efficient and simple synthetic methodologies for their synthesis with readily available substrates. -
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Synthesis of Carbon Containing Composites for Energy and Environmental Applications
The population has grown rapidly, resulting in increased energy consumption and environmental issues. Researchers are developing new materials with unique physical and chemical properties to tackle these challenges. This has led to a focus on exploring novel approaches to synthesize micro and nanomaterials for use in the energy and environmental sectors. In this study, carbon-containing catalysts were developed as photocatalysts, electrocatalysts for water splitting reactions, and electrode materials for supercapacitor application. To evaluate the physicochemical characteristics of these materials, various characterization methods were employed, including X-ray diffraction, newlineScanning Electron Microscopy, Energy Dispersive X-ray Spectrometry, X-Ray Photoelectron Spectroscopy, High-resolution Transmission electron microscopy, Fourier Transform Infrared Spectroscopy, Differential reflectance spectroscopy, Dynamic light scattering, and Thermogravimetric analysis. The electrochemical and photocatalytic studies of the prepared materials were carried out by optimizing the different parameters. The four chapters include newlineCr2AlC MAX Phase as the catalyst used for photocatalysis, bismuth ferrite/Cr2CTx MXene, cobalt ferrite/Cr2CTx MXene composites for supercapacitor and electrocatalytic water splitting, bismuth ferrite/graphitic carbon nitride/N-doped graphene quantum dots for supercapacitor application, and Cobalt ferrite/graphitic carbon nitride/N-doped graphene quantum dots for supercapacitor and newlineelectrocatalytic water splitting application. -
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Synthesis of Thiazines, Thiazinones and N-Cycloalkyl Azoles Via Novel Synthetic Routes
Heterocyclic building blocks have gained the utmost importance in recent past on the newlineaccount of their significance in biological and pharmaceutical fields. Among these newlinenitrogen and sulphur containing heterocyclic building blocks such as thiazines, newlinethiazinones and N-cycloalkyl heterocyclic motifs hold an important role in medicinal newlinechemistry. Thiazine cores are used for the treatment of various life threating diseases newlinelike cancer, cardiovascular and fabry diseases. Drugs containing thiazinone cores were used to treat Parkinson, Alzheimer s and various neuro degenerative diseases. Ncycloalkyl azole motifs are used to treat various life threating cancers like neck, lung, prostate, breast etc. As per the literature review, synthesis of these motifs are done using multi steps and harsh conditions, which limited the substrate scope. In this thesis we describe our studies on development of one pot, mild condition for newlinesynthesis of thiazinone cores using P(NMe2)3 (HMPT). We had developed HMPT [P(NMe2)3] mediated reactions towards synthesis of Carbon-Nitrogen/Carbon-Sulphur bond. The developed methodology was extended for thiazine cores as well. This new synthetic methodology is useful to synthesize various N, S-heterocycles including the novel spiro molecules. HMPT reagent under the mild and aerobic reaction conditions provided the access for many manifold immense molecules. Molecular docking studies were conducted for the synthesized compounds considering MOA-B inhibitors as target. MOA-B inhibitor motifs were approved for the treatment of Parkinson illness. The synthesized thiazine and thiazinone molecules showed good binding affinity in molecular docking studies conducted. We had developed a new strategy using T3P (1-Propanephosphonic anhydride, ~ 50 % wt, in EA solution) mediated synthetic procedure for the synthesis of N-cycloalkyl newlineazoles. -
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Synthesis spectroscopic and DFT studies of some benzimidazole and benzothiazole derivatives
Benzimidazole, benzothiazole and benzoxazole compounds and their derivatives having azole newlinemoieties are biologically active and are extensively used in pharmaceutical industry. newlineBenzimidazoles/benzothiazoles scaffolds have also been widely used as and#61552;and#8722;spacers and newlinedonor/acceptor units. The lone pair electrons and conjugated structures of these heterocyclic molecules assist in tuning of electronic properties enabling their use in devices like dye sensitized solar cells, organic light emitting diodes etc. However, the design and synthesis of organic ligands newlinefor these applications is still a challenging task. Though we have made an effort in this direction fabricating a dye sensitized solar cell with benzimidazole based sensitizer, the moderate Stokes shift and efficiency prompted us to tune these molecules and improve their electronic properties. Considering that some of the benzimidazole/benzothiazole fluorophores possessing metal-ion newlinechelating properties and having hydrogen donor-acceptor sites in close proximity play vital role in sensor and bioimaging applications, we have designed and synthesized novel fluorophores for newlinemetal ion sensing applications. Since most of the available literature shows studies on fluorophores with single excited state intramolecular proton transfer sites or dual proton transfer sites with symmetrical structures, we have considered investigating fluorophores having asymmetrical newlinestructures and proton donating sites. In this perspective, we have synthesized and conducted spectroscopic and density functional theory studies on some novel fluorophores based on benzimidazole/benzothiazole Schiff bases and the details are presented in this thesis. Chapter 1 gives an introduction to the benzimidazole/benzothiazole heterocycles and the different photophysical and chemical phenomena involved. A brief literature survey in support of our studies is presented in Chapter 2. Chapter 3 gives a brief description of the experimental methods newlineand techniques used in our work. -
Synthesis, Adsorptive Properties and Applications of Modified Aluminum Oxyhydroxide-PVA Films
Over the past few years, there has been an increasing interest in polymer films and newlinemetal-incorporated polymer films because of their distinctive characteristics and newlinepotential applications. The effectiveness of alumina or modified alumina polymer films newlineas adsorbents or catalysts is greatly influenced by their surface properties, texture, chemical composition, and thermal stability. This thesis describes the synthesis of aluminum oxyhydroxide - polyvinyl alcohol composite films by sol-gel method. The synthesized films were modified by incorporating transition metals and cross-linking agents depending on the desired application as a catalyst or adsorbent. The synthesized films were characterized using different techniques, like powder X-ray diffraction studies (pXRD), Fourier transform infrared spectra (FTIR), Raman spectra, BrunauerEmmett-Teller surface area (BET), Barrett-Joyner-Halenda (BJH) isotherm, atomic newlineforce microscopy, optical profilometry, thermogravimetric analysis, Scanning electron newlinemicroscopy (S.E.M), and X-ray photoelectron spectroscopy (XPS) to determine the newlinestructural and textural properties. The films were deployed as adsorbents for the removal of heavy metals and dyes from water as well as catalysts for industrially important organic transformations. The results of the characterization studies were used to correlate the surface characteristics and adsorptive capacities of the fabricated films. The films were found to have tuneable surface properties and enhanced adsorptive newlinebehaviour, which could be modified as per the application. Transition metalincorporated films exhibited remarkable adsorption properties for the elimination of heavy metals and organic dyes from aqueous solution. The adsorption reaction kinetics newlinewere investigated to ascertain the rate and mechanism of the reaction to improve the newlineefficiency, economic efficiency and environmental sustainability of the reaction. -
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Synthesis, Characterization and Catalytic activity of Zirconia-Ceria catalysts
The development of catalysts is critical for the economical and environmentally efficient generation of chemical compounds that underlie every aspect of our society. Catalysts are key players in research involving the discovery of pharmaceuticals, materials, and polymers. In addition, catalysis is especially powerful in bulk synthesis, allowing the production of compounds, polymers and commodity chemicals via routes that would otherwise be impossible. Ceria is the unique rare earth for which dioxide is the normal stable phase contrary to the others for which Ln2O3 is the normal stoichiometry. The applications of ceria based materials are related to a potential redox chemistry involving Ce(III) and Ce(IV), high affinity of the element for oxygen and sulphur and absorption/excitation energy bands associated with its electronic structure. Zirconium is one of the more abundant elements, and is widely distributed in the Earth's crust. Being very reactive chemically, it is found only in the combined state or as part of a complex of oxides as in zircon, elpidite, and eudialyte. Doping ceria with zirconia may improve the oxygen storage properties of ceria at three different levels. At the level of the microstructure, it inhibits surface diffusion and in turn the loss of surface area at high temperatures. At the microscopic level, substantial doping may result in the formation of an interface structure that facilitates the oxygen transport from bulk to the surface. At the atomic-level, it stabilizes the oxygen defective structure. The texture, structure and thermal stability of ceria-zirconia doped oxides are closely related to the ratio of cerium to zirconium in the solid solution. Chapter 1 comprises of the general introduction of catalysis, importance of solid acid catalysis, sulphated metal oxides, pure ceria, pure zirconia, modified ceria and zirconia. It gives a brief introduction about the nitration of toluene. The aim and objectives of the present investigation are also described at the end of this chapter. Chapter 2 comprises of a thorough literature survey on the significance of solid acid and super acid catalysts in various domains of chemical industry and importance of anion promoted zirconia and ceria catalysts. The definition of ??super acid and their classification vii on the basis of origin of the active sites are also outlined. Importance of modified metal oxides is also outlined. Chapter 3 deals with the experimental procedures and techniques employed in this investigation. Scientific aspects of the precipitation and impregnation methods were outlined. The experimental details of surface area measurements by BET method, application of X-ray powder diffraction studies for crystalline phase and size determination, elemental detection by EDAX, spectral details from FTIR and thermal stability by TGA have been described. Chapter 4 deals with the various characterization results and discussion of pure, doped and sulphated Zirconia-ceria solid acid catalysts. The bulk and surface properties of the catalyst was discussed by XRD, BET surface area, TGA and FTIR. All characterization results revealed that the incorporated sulphate ions has a significant influence on the surface and bulk properties of the ZrO2-CeO2 catalyst. The prepared catalysts are investigated for the liquid phase nitration of toluene under various reaction conditions. Chapter 5 gives with the summary and conclusion of the present study. It also gives the future scope of the present study. On the whole, zirconia-ceria solid acid catalysts were successfully synthesized by simple route. Physicochemical characterization of all these catalysts revealed that the loaded sulphated and doped metal oxides show a significant influence on the surface and bulk properties of the ZrO2 - CeO2. These catalysts are found to be active for the liquid phase nitration of toluene. Key words: Solid acid catalysis, Zirconia-Ceria, Sulphated zirconia-ceria, Nitration of toluene -
Synthesis, Characterization and Analytical Applications of Disubstituted urea/thiourea derivatives
Two Urea/Thiourea derivatives have been synthesized in good yields from Urea/Thiourea and aniline in dry media conditions by using p-TSA as catalyst under microwave assisted method and they are characterized by IR and NMR spectral analysis. There are several advantages of foresaid catalyst like rate enhancements, higher yields, easy work-up procedure and energy efficient. The reaction has been done under solvent free condition having short reaction time period, increased safety and economic advantages. This Thiourea derivatives reagent has been used for the spectrophotometric determination of palladium. The results obtained by the proposed method is accurate reproducible. The proposed method has been successfully applied for the determination of palladium(II) in some synthetic mixtures of alloy samples and mineral. This dissertation contain five chapters Chapter 1 includes significance of Urea/Thiourea derivatives, green experimental protocol, heterogeneous catalysts. It also includes Objective of the study which is a develop a new methodology for the synthesis of Urea/Thiourea derivatives. Chapter 2 includes review of literature on the synthesis of Urea/Thiourea derivatives by different varieties of techniques. Different catalysts are used for that technique. Chapter 3 describes about materials and experimental procedures which are used in this synthesis . Chapter 4 deals with the various characterization results of Urea/Thiourea derivatives. It also describes the application of N,N??-diphenylthiourea in the trace level determination of palladium. Chapter 5 gives the summary and conclusion of the present study. It also gives the future scope of the present work. Furthermore, short reaction times, good yields of products, mild reaction conditions, and easy work-up/purification are the other noteworthy advantages which make this method a valid contribution to the existing methodologies is given in this chapter. Key works: Urea/Thiourea derivatives, p-TSA, MWI, IR, NMR, and Palladium. -
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Synthesis, Characterization and Studies of Hydrazine Based Polyfunctional Ligands and their Metal Chelates
Eight new hydrazine-based zinc (II), copper (II) complexes were synthesized by reacting Zn (OAc)2.2H2O and Cu(CH3COO)2 with N'??(3,5-dibromo-2-hydroxy benzylidene) benzohydrazide (H2L1) and N'??(3,5-dibromo-2-hydroxy benzylidene) nicotinichydrazide (H2L2) respectively. The synthesized complexes were characterized by CHN analyses, IR, UV and 1H NMR. Based on these studies, square planar and octahedral geometries of the metal complexes were revealed. The synthesized metal complexes named [Zn(H2L1)2](OAc)2, [Zn(H2L1)Py](OAc)2, [ZnL2]2, [ZnL2Py], [CuL1]2, [CuL1Py], [CuL2]2 and [CuL2Py]. The formed metal complexes were investigated for DNA binding studies by fluorescence and UV spectroscopy using calf thymus DNA (CT-DNA) and DNA cleavage studies against pBR322 DNA. Both the ligands and their corresponding metal complexes showed the ability for binding to DNA through intercalation/ electrostatic binding. -
SYNTHESIS, GROWTH AND CHARACTERISATION OF AN ORGANOMETALLIC SINGLE CRYSTAL
The strong influence of single crystals in the present day technology is evident from the recent advancements in semiconductors, polarisers, transducers, infrared detectors, photosensitive materials and crystalline thin films for microelectronics and computer industries. Nonlinear optical crystals (NLO) are in great demand in view of their applications in areas like optical modulation, optical switching, frequency shifting and optical data storage for developing technologies in telecommunications and signal processing. Organometallic single crystals are specially noted among the new generation NLO crystal due their structural diversity and applications. In this present work, organometallic compounds of manganese mercury thiocyanate (MMTC) and Co2+ doped MMTC were synthesised and single crystals were grown by slow evaporation method. The grown crystals were subjected to various characterisation techniques like X-ray diffraction analysis, FT-IR analysis and UV spectroscopy. Dielectric and photo conductivity studies were also performed. The first chapter in the dissertation brings out the importance of organometallic NLO crystals. Literature survey on the NLO crystals is also included in this chapter. An introduction to solution growth techniques is given in the second chapter. All the characterization techniques used for the work are introduced in the third chapter. The fourth chapter describes the synthesis, growth and characterization studies of MMTC and Co2+ doped MMTC. The last chapter contains results and discussions leading to the conclusion. -
Synthesis, Process Parameter Control and Performance of Nano Ceramic Coatings for Diesel Engine Applications
Ceramics are non-metallic inorganic solids which are used in various forms (bulk and newlinecoatings) and environments (low and high temperature) to provide protection from newlinethermal, wear or chemical attack. Due to their high melting point, compressive newlinestrength, oxidation and corrosion resistant properties, ceramics are strong, hard, newlinebrittle and harsh environment resistant. Ceramic coatings are generally applied on newlinemetal components to either enhance their life or augment the performance of the devices they are mounted on. Furthermore, coatings being thin (few small units to hundreds of microns); they do not demand significant alteration in component design. Among the many types of coatings used in engineering applications, Thermal Barrier Coatings (TBC) and wear resistant coatings (WRC) are used to protect metallic components from thermal and mechanical damages respectively. 6 to 8%Yttria stabilized zirconia (6-8% Y2O3-ZrO2), generally designated as 8YSZ has been newlineextensively used as TBC and alpha alumina (and#945;-Al2O3) find applications as WRC. 250 to 300m thick micron grained TBC, with grain sizes typically up to 20 m or even higher are well known to thermally insulate diesel engine combustion chamber to provide enhanced fuel efficiency characteristics. 8YSZ and and#945;-Al2O3 coatings also find use in power plants, textiles, automotive and aero-space industries etc. to provide benefits like improved product quality and energy efficiency, extended wear life, reduced maintenance cycles and costs etc. Among ceramic coatings, nanostructured coatings have received further interest because of their extraordinary properties including enhanced hardness, strength, ductility, and toughness when compared with coatings with micron grained newlinemicrostructure. Nanostructured zirconia is also expected to serve as advanced TBC in newlineengine applications, although information on its feasibility and the technology is mostly classified. -
Synthesis, Spectroscopic and DFT studies of some benzimidazole and bemzothiazole derivatives
Benzimidazole, benzothiazole and benzoxazole compounds and their derivatives having azole moieties are biologically active and are extensively used in pharmaceutical industry. Benzimidazoles / benzothiazoles scaffolds have also been widely used as −spacers and
donor/acceptor units. The lone pair electrons and conjugated structures of these heterocyclic molecules assist in tuning of electronic properties enabling their use in devices like dye sensitized solar cells, organic light emitting diodes etc. However, the design and synthesis of organic ligands for these applications is still a challenging task. Though we have made an effort in this direction fabricating a dye sensitized solar cell with benzimidazole based sensitizer, the moderate Stokes shift and efficiency prompted us to tune these molecules and improve their electronic properties. Considering that some of the benzimidazole / benzothiazole fluorophores possessing metal-ion chelating properties and having hydrogen donor-acceptor sites in close proximity play vital role in sensor and bioimaging applications, we have designed and synthesized novel fluorophores for metal ion sensing applications. Since most of the available literature shows studies on fluorophores with single excited state intramolecular proton transfer sites or dual proton transfer sites with symmetrical structures, we have considered investigating fluorophores having asymmetrical structures and proton donating sites. In this perspective, we have synthesized and conducted spectroscopic and density functional theory studies on some novel fluorophores based on benzimidazole / benzothiazole Schiff bases and the details are presented in this thesis. -
Synthesize of Indigenous Natural Ester Based Liquid Dielectrics and its Performance Evaluation in Transformers
Transformer is generally considered to be the heart of the power system. Transformers are the main equipment in the transmission and distribution network to be monitored for uninterrupted flow of power. The liquid newlinedielectrics play an important role in functioning of transformer. It serves as an effective coolant and also it determines the life of transformer. Thus, the reliability of a power transformer is largely determined by the condition of insulation. The transformer oil is the bi product of petroleum. However, the usage of petroleum oil is running out of demand and there may be a severe shortage of oil exists in future. Also during its newlineuse and disposition, transformer oil is highly dangerous to aquatic and human life due to its non-biodegradability and hence it is not environment eco-friendly. This has given scope for new alternative biodegradable dielectric fluids such as natural esters, replacing the traditional mineral oil. These vegetable-oil-based liquids are non-toxic newlineand meet all the requirements for a high temperature insulating liquid. The Partial discharge pulses present in the liquid dielectric leads to breakdown of streamer development and formation of sludge. Hence it is important to analyze the Partial Discharge properties of oils. The aim of newlinethe present work is to investigate suitability of Indigenous Natural Ester newlinebased liquid dielectrics as a liquid dielectric coolant and also to analyze newlinethe partial discharge phenomena, particularly in transformers. The results obtained are well within the IEC 62770 standards. Results shows that developed indigenous natural ester oil that has better viscosity, breakdown voltage, flash point and partial discharge properties. As a result, developed indigenous oil will be an alternate for mineral oil in newlinehigh-voltage applications. -
