http://hdl.handle.net/123456789/1323 Dissertation submitted by MP -2015 batch as part of their course. 2023-06-04T18:05:11Z http://hdl.handle.net/123456789/1082 Title: “Organophosphine Catalyzed Intramolecular Hydroacylation and δ' [C(Sp3) – H] Functionalization of Activated Ynones.” Authors: Hazra, Raju; Sastry, S. S. V. Rama Abstract: We present an organophosphine catalyzed MBH-type reaction of activated ynone and the outcome is the hydroacylation of α, ß-ynone, which leads to the formation of cyclopentadione-fused arenes and heteroarenes. In addition, we also present an organophosphine catalyzed intramolecular aldol reaction of keto-ynone, which is actually an organophosphine catalyzed δ'[C(sp3 )-H]- functionalization of α, ß-ynone, leading to the formation of 3-ethynyl-3-hydroxyindanones. Both the methodology occurs at mild conditions and is tolerant to a variety of functional groups and hence we are able to synthesize a series of compound having different type of functional groups with good to excellent yield. 2019-11-15T00:00:00Z http://hdl.handle.net/123456789/1029 Title: Local Class Field Theory Authors: Binner, Damanvir Singh Abstract: Class Field Theory is a very powerful tool for answering some of the fundamental questions in Algebraic Number Theory like splitting of primes and reciprocity laws. This thesis is an attempt to understand Local Class Field Theory through the cohomological approach. It includes a deep study of the standard group co- homology as well as the Tate Cohomology. Then we describe how this machinery can be utilized to classify the finite abelian extensions of a local field in terms of norm subgroups. We also explain why this approach cannot be extended to classify the non-abelian extensions. The thesis is intended to be a liberal intro- duction to Local Class Field Theory as very detailed reasonings are provided and not much background is assumed apart from the knowledge of standard material covered in graduate courses. 2018-11-28T00:00:00Z http://hdl.handle.net/123456789/1028 Title: Investigations on the Photocatalytic Properties of Novel Layered Sillen-Aurivillius Perovskite Phases Authors: Chatterjee, Kaustav Abstract: The advent of heterogeneous catalysis has facilitated the solar assisted toxic pollutant removal and synthesis of fine chemicals. Mixed anion compounds are known to be effective photocatalyst for visible light-induced water splitting, but the available materials have been almost limited to oxynitrides and oxysulfides. In this thesis we have synthesised, single layer Sillen–Aurivillius perovskite tantalum based oxyhalide Bi 4 TaO 8 X (X= Cl, Br, I) and metal loaded Bi 4 TaO 8 Br (M@Bi 4 TaO 8 Br). The materials were prepared using conventional solid-state route and photodeposition of metals onto Bi 4 TaO 8 Br. The prepared catalysts were characterised by PXRD, FE-SEM and DRS, which inferred they were single phase, micrometre sized particles with band gap in the visible region. The prepared photocatalyst Bi 4 TaO 8 Br was used to convert RhB to Rh110 under visible light and sunlight irradiation. We observed ~40% yield at pH=7, and the percentage yield being pH dependent. The photocatalysts exhibited excellent stability under visible light irradiation as evident from the cyclic stability tests of 50 cycles in the case of RhB to Rh110. We also examined the photocatalytic activity of the prepared M@Bi 4 TaO 8 Br by degradation of RhB under visible light illumination. We observed the excellent activity of the Pd@Bi 4 TaO 8 Br with a rate constant of 0.35372 min -1 surpassing commercial state-of-the-art P25 TiO 2 (0.10359 min -1 ) by 3.4 times. Such high activity of Pd loaded catalyst is believed to be due to the presence of various active sites on its surface, owing to efficient electron transfer from CB of catalyst to the Fermi level of Pd which helps in effective separation of electron-hole pairs. Pd@Bi 4 TaO 8 Br is superior to current commercial catalysts, in terms of catalytic efficiency and recycling stability which indicated the possibility of realising industrial scale use of toxic pollutant removal under solar irradiation. The valence band maximum of Bi 4 TaO 8 Br is unusually high, owing to highly dispersive O-2p orbitals (and not Br-4p orbitals), affording a narrow band gap and enhanced stability against photocorrosion. This study suggests that Sillen–Aurivillius perovskite oxyhalides is a promising system for versatile band level tuning for establishing efficient water oxidation under visible light. 2018-11-28T00:00:00Z http://hdl.handle.net/123456789/1027 Title: 1,6-Conjugate Addition of n-Butyllithium to para-Quinone Methides: An Access to Diarylmethanes Authors: Patil, Swati; Anand, R.V. Abstract: An efficient method for the synthesis of alkyl diarylmethanes through the 1,6-conjugate addition of n-BuLi reagent to paraquinone methides (p-QMs) has been developed here with mild conditions and short reaction period. This protocol allows to unsymmetrical alkyl diarylmethanes in moderate to excellent yields using a wide range of p-QMs and n-Butyllithium reagent 2018-11-28T00:00:00Z