Faculty Publications
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Item Synthesis, characterization and third-order nonlinear optical studies of copper complexes containing 1,10-phenanthroline-5,6-dione and triphenylphosphine ligands(2011) Rudresha, B.J.; Badekai Ramachandra, B.; Sampath Kumar, H.C.; Shivakumar, K.I.; Safakath, K.; Philip, R.This research article describes the synthesis, characterization and third-order nonlinear optical studies of copper(I) complexes [Cu(Br)(N,N?-C12H6N2O2) (PPh3)] and [Cu(I)(N,N?-C12H6N 2O2)(PPh3)] abbreviated as [CuBrLPPh 3] (1) and [CuILPPh3] (2) (L = 1,10-phenanthroline-5,6- dione). Nonlinear optical properties of the complexes are investigated at 532 nm using single beam Z-scan and degenerate four-wave mixing (DFWM) techniques employing nanosecond laser pulses. The complexes show optical limiting behaviour due to "effective" two-photon absorption. The values of the effective two-photon absorption (2PA) coefficients (?), third-order nonlinear susceptibilities (?(3)), and figures of merit (F), are calculated. © 2010 Elsevier B.V. All rights reserved.Item Nonlinear transmittance and optical power limiting in magnesium ferrite nanoparticles: effects of laser pulsewidth and particle size(Royal Society of Chemistry, 2016) Perumbilavil, S.; Sridharan, K.; Abraham, A.R.; Janardhanan, H.P.; Kalarikkal, N.; Philip, R.We report comparative measurements of size dependent nonlinear transmission and optical power limiting in nanocrystalline magnesium ferrite (MgFe2O4) particles excited by short (nanosecond) and ultrashort (femtosecond) laser pulses. A standard sol-gel technique is employed to synthesize particles in the size range of 10-50 nm, using polyvinyl alcohol as the chelating agent. The structure and morphology of the samples are studied using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Growth of the particles in time is tracked through Fourier transform infrared spectroscopy. Nonlinear transmission measurements have been carried out using the open aperture Z-scan technique employing 532 nm, 5 nanosecond pulses and 800 nm, 100 femtosecond pulses, respectively. The measured optical nonlinearity is primarily of a reverse saturable absorption (RSA) nature, arising mostly from excited state absorption for nanosecond excitation, and two-photon absorption for femtosecond excitation. The optical limiting efficiency is found to increase with particle size for both cases. The calculated nonlinear parameters indicate that these materials are potential candidates for optical limiting applications. © The Royal Society of Chemistry.Item Synthesis and application of Zr-metal–organic framework for simultaneous detection and rapid adsorption of p-nitrophenol from water(Institute for Ionics, 2023) Nimbalkar, M.N.; Badekai Ramachandra, B.R.The p-nitrophenol is a prime raw material in the manufacturing of pharmaceutical drugs, fungicides and insecticides. The effluents from these industries contain p-nitrophenol and are harmful to human and aquatic life. Hence, development of fast detection and efficient disposal process of p-nitrophenol in wastewater is a major concern. In this study, fluorescent active smart metal–organic framework (MOF) was employed for the simultaneous detection and adsorptive removal of p-nitrophenol from water. Photoluminescence active zirconium-based metal–organic framework having isostructural with UiO-66 framework was synthesized by using mixed ligand strategy with the replacement of BDC (1,4-Benzenedicarboxylic acid) ligand from 10 to 30 mol% with H3ntb ligand (4,4ʼ,4ʼʼ-Nitrilotrisbenzoic acid, in house synthesised fluorescence active trifunctional ligand). The powder X-ray diffraction (PXRD), analysis of the synthesised MOF confirms face centred cubic (FCC) crystal structure similar to pristine UiO-66. From Fourier transform infrared spectroscopy (FTIR), the peak at 1251 cm−1 for the tertiary amine group validated the presence of H3ntb ligand. The obtained MOFs have the surface area from 1039 m2g−1 to 949.1 m2g−1 and pore volume ranging from 0.04973 cm3g−1 to 0.05160 cm3g−1. Experimental results indicated that MOF was able to detect p-nitrophenol at low concentration (≈35 μM) and to remove rapidly (< 10 min) it from the aqueous solution. The adsorption process obeys Langmuir isotherm (monolayer adsorption capacity is 62 mgg−1) and kinetics by Elovich model indicating adsorption nature as chemisorption on a heterogeneous surface. Graphical abstract: [Figure not available: see fulltext.] © 2022, The Author(s) under exclusive licence to Iranian Society of Environmentalists (IRSEN) and Science and Research Branch, Islamic Azad University.Item The γ-Valerolactone (GVL) as Innoxious Reaction Media for the Synthesis of 2-Aryl-2H-Indazoles via C-N and N-N Bond Formation under Cu(I)-Catalyzed Ligand and Base Free Conditions(Taylor and Francis Ltd., 2024) Singh, L.S.; Kant, K.; Banerjee, S.; Sengupta, R.; AlObaid, A.A.; Pal, M.; Dutta, S.; Aljaar, N.; Malakar, C.C.An efficient method for N-arylation and N-N bond formation has been developed using an innoxious reaction medium, γ-valerolactone (GVL), as both a solvent and a ligand. The strategy involves utilizing CuI as a catalyst under conditions free of external ligands and bases. Various aldehyde and amine derivatives with different functional groups were investigated, resulting in the production of 2-aryl-2H-indazole compounds with yields ranging from 75% to 93%. This study highlights the effectiveness of GVL, a solvent derived from biomass, as a reaction medium and ligand in a multicomponent reaction. © 2023 Taylor & Francis Group, LLC.