Faculty Publications
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Item New luminescent 2-methoxy-6-(4-methoxy-phenyl)-4-p-tolyl-nicotinonitrile: Synthesis, crystal structure, DFT and photophysical studies(2014) Ahipa, T.N.; Kamath, P.R.; Kumar, V.; Vasudeva Adhikari, A.V.In the current communication, we report the synthesis, spectroscopic, crystal structure, DFT and photophysical studies of a new nicotinonitrile derivative, viz. 2-methoxy-6-(4-methoxy-phenyl)-4-p-tolyl-nicotinonitrile (2) as a potential blue light emitting material. The compound 2 was synthesized in good yield via a simple route. The acquired spectral and elemental analysis data were in consistent with the chemical structure of 2. The single crystal study further confirms its three dimensional structure, molecular shape, and nature of short contacts. Its DFT calculations reveal that compound 2 possesses a non-planar structure and its theoretical IR spectral data are found to be in accordance with experimental values. In addition, its UV-visible and fluorescence spectral measurements prove that the compound exhibits good absorption and fluorescence properties. Also, it shows positive solvatochromic effect when the solvent polarity was varied from non-polar to polar. © 2014 Elsevier B.V. All rights reserved.Item The hierarchies of hydrogen bonds in salts/cocrystals of isoniazid and its Schiff base - A case study(Royal Society of Chemistry, 2016) Oruganti, M.; Khade, P.; Das, U.K.; Trivedi, D.R.A series of two salts of isoniazid and two cocrystals of its Schiff base have been synthesised and characterized using FT-IR, 1H-NMR, DSC, XRPD and SCXRD. The crystal structures with 2,5-dihydroxybenzoic acid, 2,6-dihydroxy benzoic acid, 3-aminobenzoic acid and o-phthalic acid have been deduced. In all complexes the involvement of pyridine N (proton transfer/robust synthon) is noticed. The unit cell similarity index was calculated between two cocrystals (N-(propan-2-ylidene)isonicotinohydrazide)·(2,5-dihydroxybenzoic acid) and (3-aminobenozic acid)·(N-(propan-2-ylidene)isonicotinohydrazide). Furthermore, the index was compared with the reported complexes and it was found to be close to zero indicating isostructurality. The correlation between the NPyr-H?O (acid) hydrogen bond distance for the reported cocrystals and their corresponding pKa values has been deduced and validated. © The Royal Society of Chemistry 2016.Item Air-Stable Cobalt(II) and Nickel(II) Complexes with Schiff Base Ligand for Catalyzing Suzuki–Miyaura Cross-Coupling Reaction(Pleiades journals, 2018) Ansari, R.M.; Kumar, L.M.; Badekai Ramachandra, B.R.The Co(II) complex [Co{C6H4–1,2-(N=CH–C6H4O)2}] (I) and Ni(II) complex [Ni{C6H4–1,2-(N=CH–C6H4O)2}] (II) with Schiff base of o-phenylenediamine and salicylaldehyde have been synthesized. The structure of the ligand and its complexes were derived on the basis of various techniques such as elemental analysis, mass, FT-IR, electronic spectra and magnetic susceptibility. From the Singal crystal X-ray diffraction (SCXRD) analysis techniques (CIF file CCDC no. 1498772 (II)), it has been confirmed that the Schiff base ligand (L), coordinates to the metal ion in a tetradentate fashion through the nitrogen and oxygen atom. In addition, the square planar geometry of Ni(II) complex also has been confirmed from SCXRD. Electronic spectra, mass spectra, and magnetic susceptibility measurements reveal square planar geometry for the Co(II) complex. Synthesized complexes were used in cross-coupling of arylhalides with phenylboronic acid. The transformation offers products in good yields using 0.02 mmol catalysts loading, thereby proving the efficiency of the complexes as catalysts for Suzuki–Miyaura reaction. © 2018, Pleiades Publishing, Ltd.Item Functionalized 1,3-dipyrrolyl-1,3-diketone difluoroboron complexes(Royal Society of Chemistry, 2025) Shenoy, A.M.; Fernandes, P.P.; Lakshmi, V.BF2 complexes of 1,3-dipyrrolyl-1,3-diketones are highly emissive compounds and well known to be ?-electronic anion-responsive systems because of their role in the formation of ion-pair assemblies. Despite their impressive electronic properties, their broader potential remains unexplored. Here, we synthesized a series of novel mono-functionalized ?-electronic BF2 complexes of 1,3-dipyrrolyl-1,3-diketones. Controlled functionalization was achieved by selectively introducing formyl, iodo, nitro and amine groups at the ?-position of the unsubstituted pyrrole of 1,3-dipyrrolyl-1,3-diketone BF2 complexes. Single crystal X-ray diffraction studies of compounds 2 and 4 provided definitive evidence of their molecular structures and confirmed selective functionalization. Detailed photophysical and electrochemical studies revealed the alteration of electronic properties through the choice of functional groups as evidenced by distinct absorption and emission profiles. Furthermore, DFT calculations complemented the experimental findings by providing insights into the bandgap energies and molecular stability of the compounds. These functionalized BF2 complexes represent valuable building blocks for developing new derivatives with applications spanning organic electronics, bioimaging, and chemosensors. © 2025 The Royal Society of Chemistry.Item Extracellular biosynthesis of CuO-TiO2 nanocomposites using Alcaligenes aquatilis for the photodegradation of reactive and azo dyes under visible light irradiation(Springer, 2025) Agarwalla, S.; Shetty K, V.In this study, CuO/TiO2 nanocomposites were biologically synthesized using cell-free supernatant (CFS) of Alcaligenes aquatilis growth culture by two-step synthesis method, one-pot method with sequential addition of precursors, and one-pot method with simultaneous addition of precursors. The one-pot method with simultaneous addition of precursors was found to be the best method for the synthesis in terms of degradation of reactive blue-220 (RB-220) and acid yellow-17 (AY-17) dyes under visible light irradiation. CuO/TiO2 nanocomposite was found to have the crystallite size of 14.7nm and the bandgap energy of 2.5 eV. The effect of synthesis parameters such as synthesis time, pH of CFS, and the ratio of Cu to Ti in the synthesis mixture on the photocatalytic degradation efficacy of these nanocomposite structures under visible light irradiation was studied. The optimum conditions for the synthesis of CuO/TiO2 nanocomposite particles by one-pot method with simultaneous addition of precursors were found to be pH 12 of CFS, synthesis duration of 24 h, and molar ratio of Cu to Ti in the synthesis mixture as 1:22 for RB-220 dye and 1:25 for AY-17 degradation. CuO/TiO2 nanocomposite particles synthesized under the optimum conditions and without any calcination could degrade RB-220 and AY-17 dyes completely in 120 min and 150 min, respectively. The kinetics of degradation of RB-220 and AY-17 by CuO@TiO2 nanocomposite particles followed first-order kinetic model with rate constant of 0.028 min?1 and 0.018 min?1, respectively. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2023.Item Fabrication of CuxO/TiO2 hybrid nanocomposite by the synergetic effect of mixed phytoextract of agro-waste materials for enhanced visible-light-induced photocatalytic activity in degradation of ciprofloxacin(Elsevier Ltd, 2025) Shetty, P.; Shetty Kodialbail, V.The current study presents the environmentally friendly method for the synthesis of visible light active CuxO/TiO2 nanocomposite using the mixed plant extracts of areca nut exocarp (peel) and soapnut pericarp (shell) for photocatalytic degradation of ciprofloxacin, an antibiotic which is an emerging water contaminant. CuxO/TiO2 nanocomposite was synthesised by one pot method by simultaneous addition of precursors using the mixed aqueous extract. It consisted of CuO, Cu2O and TiO2 in all the crystalline phases with a band gap energy of 1.7 eV. The nanocomposite exhibited mixed morphology consisting of needle-like and particulate structures. The CuxO/ TiO2 nanocomposite facilitated 94 % degradation of 10 ppm ciprofloxacin within a span of 120 min under visible light irradiation. The CuxO/ TiO2 nanocomposite synthesized using the mixed extract exhibited superior photocatalytic activity than that synthesized solely with either areca nut peel extract or soap nut shell extract. The phyto-fabricated CuxO/ TiO2 nanocomposite showed better visible light-mediated photocatalytic activity than the phyto-fabricated CuxO, phyto- fabricated TiO2 and Degussa P-25. The kinetics of degradation followed pseudo-first order kinetic model with the rate constant of 0.0218 min?1. Thus, the phyto-fabricated CuxO/ TiO2 demonstrated a good potential as a photocatalyst to harness solar light in the treatment of wastewater contaminated with pollutants of emerging concern. © 2025 Elsevier B.V.Item Efficient removal of toxic dyes and nitrophenol using Graphene Oxide-ZrO2 hybrid catalysts(Elsevier Ltd, 2025) Amudha, A.; Mahendra, K.; Yashodhara, I.; Pattar, J.; Anil Rao, H.N.; Shashikala, H.D.; Hosakoppa, S.N.In the current study, efficient removal of industrial dyes and nitrophenol by ZrO2–GO catalyst has been reported. ZrO2–GO nanoparticles were prepared using the hydrothermal technique and are characterized using X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Transmission Electron Microscopy (TEM), Photoluminescence (PL), Raman, and UV–visible spectroscopy techniques. The ability of the nanoparticles to degrade Methylene Blue (MB), Crystal Violet (CV), and Nitrophenol (NP) was examined for their photocatalytic activities. Results revealed that there is an increase in the crystallite size and pore size increased almost 2 times after adding 2 % GO in ZrO2. The addition of GO into ZrO2 also caused a decrease in the PL intensity and energy gap indicating an increase in the charge carriers. ZrO2–GO nanoparticles showed photocatalytic degradation of 90 % (70 min), 98 % (90 min), and 70 % (120 min) for MB, CV, and NP respectively. © 2025 Elsevier B.V.Item Solvothermally synthesized dopant-free anatase-titania nanostructures for efficient photocatalytic degradation of crystal violet under violet irradiation(Elsevier Ltd, 2025) Mohapatra, A.; Murugesan, S.; Anandhan, S.The anatase polymorph of titania is known for its photocatalytic behavior. In this study, titania nanoparticles synthesized through sol-assisted solvothermal process carried out in an autoclave were utilized as photocatalyst under violet radiation for the degradation of a model pollutant, namely crystal violet. The presence of titania in the anatase form was confirmed by x-ray diffraction. Electron microscopy revealed the coexistence of rod-like and spherical-shaped structures in the nano-titania. The average diameters were 9.8 nm and 12 nm for the spherical nanoparticles and the cylindrical ones, respectively. The band gap energy of titania as calculated from the uv–vis spectroscopy was 3.22 eV, which is in line with its theoretical value. The specific surface area of the nano-titania was 39.179 m2/g, and the total pore volume was 0.05 cc/g, which indicates the presence of large number of active sites on the surface of the photocatalyst for the adsorption of pollutant molecules. Excitation and emission spectra of titania were acquired using photoluminescence spectroscopy to ascertain the presence of surface defects. Subsequently the photocatalytic degradation of crystal violet using the anatase titania nanoparticles under violet light irradiation was studied. Under violet irradiation, the dopant-free anatase titania was able to efficiently photodegrade (at loading of 200 mg/L) 1L crystal violet solution of 20 ppm concentration within 90 minutes. The results indicate that this nano-titania could be used an alternate in the place of the systems reported hitherto in literature, which were either doped with heavy metal-based systems or blended with graphene. The result is a leap forward in sustainable water treatment. © 2025 Elsevier Ltd and Techna Group S.r.l. All rights are reserved, including those for text and data mining, AI training, and similar technologies.