Faculty Publications

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    The hydrogen peroxide-mediated oxidation of biorenewable furfural to 2(5H)-furanone using heteropolyacids supported on ammonium y zeolite as the catalyst
    (Elsevier Ltd, 2020) Tiwari, R.; Bhat, N.S.; Mal, S.S.; Dutta, S.
    A series of heteropolyacid supported on ammonium Y zeolite (HPA-NH4YZ) catalysts were prepared and used for the catalytic oxidation of furfural to 2(5H)-furanone in aqueous hydrogen peroxide. The catalysts were characterized by PXRD, FTIR, TGA, and SEM analyses. The organic-solvent-free reaction was optimized on temperature, duration, loading of catalyst, and the equivalent of H2O2. The 20%PTA-NH4YZ catalyst showed the best catalytic activity giving 2(5H)-furanone in 40% isolated yield by solvent extraction under optimized conditions (20wt% cat., 100°C, 90min, 7.5eq. 30%H2O2). In addition, around 20% of succinic acid was recovered from the aqueous layer. © 2020 Elsevier Ltd. All rights reserved.
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    Cobalt complexes in [EMIM]Cl - A catalyst for oxidation of alcohols to carbonyls
    (2010) Ramakrishna, R.; Badekai Ramachandra, B.
    A coordination complex system consisting of Cobalt (II)-Schiff bases with triphenylphosphine were synthesized and characterized. These catalysts were effective in the oxidation of primary and secondary alcohols. The oxidation reactions were carried out in ethyl-methyl-imidazolium ionic liquid in presence of NaOCl. Higher catalytic activity was observed for CoL1. © 2009 Elsevier B.V. All rights reserved.
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    Catalytic oxidation of alcohols by nickel(II) Schiff base complexes containing triphenylphosphine in ionic liquid: An attempt towards green oxidation process
    (2010) Ramakrishna, D.; Badekai Ramachandra, B.; Karvembu, R.
    A series of square planar nickel(II) complexes containing N,O donor Schiff base ligand, i.e. N-(2-pyridyl)-N?-(5-substituted-salicylidene)hydrazine and triphenylphosphine, have been synthesized and characterized by analytical and spectral methods. Catalytic activities of all the complexes have been studied for the oxidation of alcohols in ionic liquid media using NaOCl as oxidant. © 2009 Elsevier B.V. All rights reserved.
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    Palladium-Schiff base-triphenylphosphine catalyzed oxidation of alcohols
    (2010) Dileep, R.; Badekai Ramachandra, B.
    Novel palladium(II)-N-(2-pyridyl)-N'-(5-R-salicylidene) hydrazine triphenylphosphine complexes were synthesized and characterized by UV, IR, 1HNMR and31P NMR spectral analysis, C, H, N analysis andmagnetic susceptibilitymeasurements. The complexes were effective in the catalytic oxidation of primary and secondary alcohols in presence of N-methyl-morpholine-Noxide as oxidant. The oxidation reactions were carried out in dichloromethane. A mechanistic study of the above reactions has been proposed. Copyright© 2010 JohnWiley & Sons, Ltd.
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    Green conversion of alcohols to carbonyls catalyzed by novel ruthenium-Schiff base-triphenylphosphine complexes
    (2011) Ramakrishna, D.; Badekai Ramachandra, B.
    A series of new RuII-Schiff base complexes of containing Ph 3P has been prepared and characterized. The complexes have been used as catalysts for the oxidation of alcohols in [EMIM]Cl ionic liquid-NaOCl system. Higher catalytic activity was found for RuL1. A plausible mechanism has been proposed. © 2010 Elsevier B.V. All rights reserved.
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    Transition metal complexes of 5-bromosalicylidene-4-amino-3-mercapto-1,2,4- triazine-5-one: Synthesis, characterization, catalytic and antibacterial studies
    (Serbian Chemical Society, 2011) Ramasubramanian, A.S.; Badekai Ramachandra, B.; Dileep, R.; Rani, S.
    Transition metal complexes of 5-bromosalicylidene-4-amino-3-mercapto-1,2,4- triazine-5-one with metal precursors, such as Cu(II), Ni(II), Co(II) and Pd(II), were synthesized and characterized by physico-chemical and spectroscopic techniques. All the complexes are of the ML type. Based on analytical, spectral data and magnetic moments, the Co(II) and Ni(II) complexes were assigned octahedral geometries, while the Cu (II) and Pd(II) complexes square planar. A study on the catalytic oxidation of benzyl alcohol, cyclohexanol, cinnamyl alcohol, 2-propanol and 2-methyl-1-propanol was performed with N-methylmorpholine-N-oxide (NMO) as co-oxidant. All the complexes and their parent organic moiety were screened for their biological activity on several pathogenic bacteria and were found to possess appreciable bactericidal properties. © 2011 Copyright (CC) SCS.
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    A catalytic process for the selective oxidation of alcohols by copper (II) complexes
    (2011) Ramakrishna, D.; Badekai Ramachandra, B.
    Novel copper (II)-N-(2-pyridyl)-N'-(5-R-salicylidene) hydrazine triphenylphosphine complexes have been synthesized and characterized. The complexes were effective in the catalytic oxidation of primary and secondary alcohols in presence of periodic acid (H5IO6) as oxidant. The oxidation reactions were carried out in acetonitrile. Electrochemical electron transfer study reveals CuII-CuI reduction in methanolic solutions. A mechanistic study of the above reactions has been proposed. © 2011 Elsevier B.V. All rights reserved.
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    Identification of robust synthon in the molecular salts of 2-aminothiazole with substituted benzoic acids: A case study
    (Springer India sanjiv.goswami@springer.co.in, 2014) Oruganti, M.; Pallepogu, R.; Trivedi, D.R.
    Six new salts of an API intermediate 2-aminothiazole with different carboxylic acid coformers were synthesized and characterized by IR (Infrared spectroscopy), 1H-NMR, DSC (Differential scanning calorimetry), XRPD (X-ray powder diffraction) and single crystal XRD. The crystal structure of the salts with benzoic acid, 2,3-, 2,4-, 2,5-, 2,6- dihydroxybenzoic acids and 2,4-dinitrobenzoic acid were determined. The thiazole moiety exhibited solvent (polarity) assisted tautomerism in all reported salts and proton transfer was noticed to the ring N of thiazole due to which two point supramolecular synthon N+-H(thiazole)?O-(acid), N-H(amine)?O-(acid) was observed. The crystal structures were studied with respect to the positional effect of the competing functional groups like hydroxyl (-OH) and nitro (-NO2) as well as their donor and acceptor abilities for hydrogen bonding. The presence of the non-conventional hydrogen bond (C-H?O) has been found to play a critical role in the formation of secondary supramolecular architectures. © 2014 Indian Academy of Sciences.
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    Multi-wall carbon nanotube-NiO nanoparticle composite as enzyme-free electrochemical glucose sensor
    (Elsevier, 2015) Prasad, R.; Badekai Ramachandra, B.R.
    We report a simple, solvent-free method to decorate multi-walled carbon nanotubes (MWCNTs) with nickel oxide nanoparticles (NiO-NPs). The as prepared NiO-MWCNT composite were characterised by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy. The enzyme-free modified carbon paste electrode (CPE) was fabricated using as-synthesised composite material and investigated for glucose sensing. The 10% NiO-MWCNTs composites sensor showed excellent electro-catalytic activity towards direct glucose oxidation. The sensitivity of this sensor is found to be 1696 ?A mM-1 cm-2 and 122.1 ?A mM-1 cm-2 and the limit of detection (LOD) was found to be 11.04 nM and 31 ?M for the linear response over glucose concentration ranging from 1-200 ?M to 0.5-9.0 mM, respectively. Furthermore, the 10% NiO-MWCNTs sensor also showed excellent anti-interference ability, high stability and good reproducibility. Hence, due to simple method of material preparation, easy sensor fabrication and excellent electro catalytic activity towards glucose oxidation, the 10% NiO-MWCNT/CPE is a potential material for the development of enzyme-free sensor for reliable glucose determination. © 2015 Elsevier B.V. All rights reserved.
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    Ceria-samarium binary metal oxides: A comparative approach towards structural properties and soot oxidation activity
    (Elsevier B.V., 2018) Anjana, A.P.; Geethu, J.; P, M.R.; Prasad Dasari, H.P.; Lee, J.-H.; Harshini, H.; Bhaskar Babu, G.U.
    Binary metal oxides of CeO2-Sm2O3 (CSx, x varies from 10 to 90 mol%) along with pure CeO2 and Sm2O3 were synthesised successfully by the EDTA-Citrate method. From XRD, Raman spectroscopy and UV–vis DRS results, the whole composition of metal oxides exist in three phases: (fluorite phase (F) (CS10-CS30), bi-phase (fluorite (F) + cubic (C)) (CS30-CS90) and cubic phase (C) (Sm2O3)). For CSx samples, the calculated band gap energy values obtained from the UV–vis DRS results were in between 3.0–5.1 eV and fluorite phase samples (CS10–CS30) displayed lower band gap energy values (3.04–3.07 eV) than compared to the samples in other phases. Similarly, from XPS analysis, fluorite phase samples (CS10–CS30) showed higher surface oxygen vacancy concentration than compared to samples in other phases. Catalytic activity for soot oxidation is carried out on CSx samples, and the T50 temperature is in between 480–540 °C. Fluorite phase samples (CS10 CS30) showed higher surface area, lower degree of agglomeration, lower band gap energy, higher oxygen vacancy concentration and better catalytic activity for soot oxidation. Among all the CSx samples, CS10 sample displayed highest surface area (38 m2/g), lowest degree of agglomeration (0.36), lowest band gap energy (3.04 eV), highest oxygen vacancy concentration (64%) and highest soot oxidation activity (T50 = 480 °C). The order of the soot oxidation activity of CSx samples followed the same trend of band gap energy values. © 2018 Elsevier B.V.