@article { ISI:000230879600018, title = {Stereoselectivity ratios in a simple Diels-Alder reaction in aqueous salt solutions of alcohols}, journal = {Tetrahedron}, volume = {61}, number = {33}, year = {2005}, month = {AUG}, pages = {8025-8030}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

This is the first exhaustive report on the variation of stereoselectivity ratios for a simple Diels-Alder reaction between cyclopentadiene and methyl acrylate. The reaction was carried out in aqueous mixtures of methanol, ethanol, propan-1-ol and butan-1-ol in presence of LiClO4, LiCl, NaCl, KCl, CaCl2 and MgCl2. The endo sterecisomer decreases with the increase in carbon chain length of the alcohol. However, LiClO4, a salting-in agent in water becomes salting-out in aqueous mixtures of alcohols. The solvent properties, thus can be attuned by adjusting the amount of solvents and salts. (c) 2005 Elsevier Ltd. All rights reserved.

}, keywords = {aqueous alcohols, Diels-Alder reaction, endolexo ratios, salts}, issn = {0040-4020}, doi = {10.1016/j.tet.2005.06.010}, author = {Deshpande, Suvarna S. and Kumar, Anil} } @article { ISI:000226532100001, title = {Synthesis, characterization and photo catalytic degradation of aqueous eosin over Cr containing Ti/MCM-41 and SiO2-TiO2 catalysts using visible light}, journal = {Journal of Molecular Catalysis A - Chemical}, volume = {226}, number = {2}, year = {2005}, month = {FEB}, pages = {149-154}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Two series of samples were prepared namely Cr-Ti/MCM-41 and Cr/SiO2-TiO2 keeping Si/Ti mole ratio same, with different Cr loading. The physico-chemical properties of the samples were characterized by different analytical techniques such as XRD, FTIR, TEM, low temperature N-2 sorption, and UV-vis diffused reflectance spectroscopy. The impregnated TiO2 was in anatase form. The crystallite size was determined from Scherrer equation as well as by TEM. There is a difference between the shapes of nitrogen adsorption isotherms with and without Cr-loaded Ti/MCM-41 samples. The rate of nitrogen adsorption was found to increase with decrease in Cr content at lower P/P-0 for Cr-Ti/MCM-41 samples due to the blocking of the pores with Cr. All MCM-41 samples exhibited pore sizes from 24 nm to 32 nm. UV-vis diffused reflectance spectra of all Cr-loaded samples showed red shift of their absorption edges. Photo degradation of eosin dye was studied using visible light. (C) 2004 Elsevier B.V. All rights reserved.

}, keywords = {Cr-Ti/MCM-41, Cr/SiO2-TiO2, eosin, photo degradation, visible light}, issn = {1381-1169}, doi = {10.1016/j.molcata.2004.09.055}, author = {Awate, S. V. and Jacob, Nalini E. and Deshpande, Suvarna S. and Gaydhankar, T. R. and Belhekar, Anagha A.} } @article { ISI:000271443200024, title = {Synthesis of N-methylaniline by aniline alkylation with methanol over Sn-MFI molecular sieve}, journal = {Catalysis Letters}, volume = {133}, number = {1-2}, year = {2009}, month = {NOV}, pages = {175-184}, publisher = {SPRINGER}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

Sn-MFI molecular sieves (Tin silicalite-1) with SiO(2)/SnO(2) molar ratio of 50-150 were synthesized and characterized. Elemental analysis, XRD and DRUV-vis confirmed that prepared samples were of MFI zeolite structure and Sn was incorporated in MFI framework. Vapor phase methylation of aniline over Sn-MFI was systematically studied and optimizations of process parameters were carried out. Sn-MFI (SiO(2)/SnO(2) = 50) was found to be optimum catalyst with 55\% aniline conversion and 60\% N-methylaniline selectivity. At lower space velocity (higher contact time) of 1 h(-1), aniline conversion was found to be increased to 71\% with reduction in N-methylaniline selectivity to 39\% and increased in N,N-dimethylaniline selectivity to 58\%. The reaction follows first order kinetics with respect to aniline having activation energy of 7.3 kcal/mol.

}, keywords = {Aniline, Lewis acid, Methanol, N-methylaniline, Sn-MFI}, issn = {1011-372X}, doi = {10.1007/s10562-009-0143-4}, author = {Niphadkar, P. S. and Joshi, P. N. and Gurav, H. R. and Deshpande, Suvarna S. and Bokade, Vijay V.} } @article { ISI:000338348000023, title = {Synthesis, characterization and photocatalytic behavior of TiO2-SiO2 mesoporous composites in hydrogen generation from water splitting}, journal = {Journal of Materials Science}, volume = {49}, number = {18}, year = {2014}, month = {SEP}, pages = {6383-6391}, publisher = {SPRINGER}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

TiO2-SiO2 mesoporous composite photocatalysts with different proportions (in wt\%) of TiO2 and SiO2 (TiO2-SiO2 = 20:80, 40:60, 60:40, 80:20 and 100:0) were prepared by loading TiO2 on as-synthesized Si-MCM-41 using sol-gel method. The physicochemical properties of composites were investigated by powder X-ray diffraction, N-2 adsorption-desorption measurements, transmission electron microscopy and UV-Vis diffuse reflectance spectroscopy. It is revealed that the titanium species are dispersed as TiO2 having interaction with the surface of the support. Even at high TiO2 loading, the mesostructural feature of MCM-41 was found to be intact without pore blockages. The change in morphology of TiO2 particle was observed with increase in TiO2 loading which may be due to different environment for the growth of TiO2. The photocatalytic evaluation of composites was carried out in production of hydrogen by water splitting. Among the prepared samples, mesoporous composite containing 60 \% TiO2 (MTi60) has shown the best results (0.08805 mmol of H-2/h/g of TiO2) compared to other composite photocatalysts. The catalytic performance of this sample was further enhanced (similar to 8 times) after loading 1 \% Pt in water splitting (0.70161 mmol of H-2/h/g of TiO2). 1 \% Pt loaded on pure TiO2 (MTi100) showed hydrogen evolution of the magnitude 0.26 mmol of H-2/h/g of TiO2. TiO2-SiO2 mesoporous composite photocatalyst showed much higher activity (similar to 1.9 times) than amorphous silica-embedded titania catalyst having same composition.

}, issn = {0022-2461}, doi = {10.1007/s10853-014-8365-2}, author = {Niphadkar, P. S. and Chitale, S. K. and Sonar, S. K. and Deshpande, Suvarna S. and Joshi, P. N. and Awate, S. V.} } @article { ISI:000372156200013, title = {Synthesis of Sn-containing anatase (TiO2) by sol-gel method and their performance in catalytic water splitting under visible light as a function of tin content}, journal = {Materials Letters}, volume = {171}, year = {2016}, month = {MAY}, pages = {50-54}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Sol-gel route was employed to prepare a series of Sn-containing anatase with different molar (Ti/Sn) ratios ranging from 49 to 1. Samples were characterized by powder XRD, UV-vis, XPS, SEM, EDAX, low temperature N-2 sorption technique and Raman Spectroscopy. Except anatase phase, no other crystalline phase was observed when Ti/Sn molar ratio was varied from 49 to 9 and for Sn free sample. However, further decrease in the ratio lead to the appearance of additional SnO2 phase whose peak intensities were increased with the increase in the tin content. Irrespective of tin content, all samples showed red-shift in UV-vis spectra. Moreover, samples showed Raman shift to higher vibration side from 143 cm(-1) to 147 cm(-1) indicating the doping of Sn2+ into TiO2. By virtue of low band gap, anatase crystallite size and an absence of XRD visible SnO2, ST (19) has shown maximum photocatalytic activity upon 1 wt\% Pt loading. It has exhibited the highest rate (0.1264 mmole/g/h) for visible light induced hydrogen evolution by water splitting. (C) 2016 Elsevier B.V. All rights reserved.

}, keywords = {Semiconductors, Sn2+ doped titania, SnO2/TiO2, Sol-gel preparation, visible light, water splitting}, issn = {0167-577X}, doi = {10.1016/j.matlet.2016.02.055}, author = {Tangale, N. P. and Niphadkar, P. S. and Samuel, V. and Deshpande, Suvarna S. and Joshi, P. N. and Awate, S. V.} }