@article {43396, title = {Comparative catalytic activity of Mn(Salen) complexes grafted on SBA-15 functionalized with amine, thiol and sulfonic acid groups for selective aerial oxidation of limonene}, journal = {Microporous and Mesoporous Materials}, volume = {104}, year = {2007}, month = {AUG}, pages = { 225-235}, abstract = {SBA-15 molecular sieves were functionalized with propylamine, propylthiol and propylsulfonic acid groups. Mn(Salen)Cl complexes were grafted on these organo-functionalized SBA-15. The support and the type of organo-functional group influenced the electronic structure (oxidation state and redox behavior) and chemo selectivity of the Mn-complexes in the oxidation of limonene. The Mn ions were reduced from +3 to +2, the extent of this reduction on different supports decreasing in the order: SBA- 15-pr-SH > SBA- 15-prSO(3)H > SBA-15-pr-NH2- Mn(Salen)Cl supported on propylthiol-functionalized SBA-15 yielded the 1,2-limonene epoxide with 100\% chemo- and regioselectivity. Higher electron density at the site of Mn ions and the consequent lower redox potential of the Mn-complexes on immobilization are the probable causes for their efficient and selective catalytic activity. Solvents, additives (N-MeIm) and co-reagents (iso-butyraldehyde), which facilitated formation of Mn2+ ions, enhance the catalytic activity. A part of the Mn complexes was leached out of the solid phase during the reaction and the extent of this with different catalysts decreased in the order: SBA-l5-pr-NH2-Mn(Salen)Cl > SBA- 15-pr-SO3H-Mn(Salen)Cl > SBA- 15-pr-SH-Mn(Salen)Cl. (C) 2007 Elsevier Inc. All rights reserved}, doi = {10.1016/j.micromeso.2007.02.026}, author = {Salkia, Lakshi and Srinivas, Darbha and Ratnasamy, Paul} } @article { ISI:000299911600015, title = {Challenges and opportunities in biofuels production}, journal = {Indian Journal of Chemistry Section A-Inorganic Bio-Inorganic Physical Theoretical \& Analytical Chemistry}, volume = {51}, number = {1-2}, year = {2012}, month = {JAN}, pages = {174-185}, publisher = {NATL INST SCIENCE COMMUNICATION-NISCAIR}, address = {DR K S KRISHNAN MARG, PUSA CAMPUS, NEW DELHI 110 012, INDIA}, abstract = {

Biofuels are attractive alternative to petroleum diesel. They are renewable, non-toxic, biodegradable, carbon neutral and lead to reduced tailpipe emissions. This article presents the current state-of-art processes of their production and discusses the opportunities and future challenges in this area of research.

}, keywords = {Biodiesel, biofuels, Deoxygenation, Hydrotreatment, Renewable fuels, Solid catalysts, Transesterification (fatty acid glycerides), Vegetable oils/fats}, issn = {0376-4710}, author = {Srinivas, Darbha and Satyarthi, Jitendra Kumar} } @article { ISI:000315069400009, title = {Catalytic activity of ZIF-8 in the synthesis of styrene carbonate from CO2 and styrene oxide}, journal = {Catalysis Communications}, volume = {32}, year = {2013}, month = {FEB}, pages = {36-40}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The catalytic activity of ZIF-8 in the synthesis of styrene carbonate from carbon dioxide and styrene oxide is presented. ZIF-8 crystals displayed catalytic activity even at temperatures as low as 50 degrees C, with styrene carbonate yields as high as similar to 54\% at 100 degrees C. In contrast to many prior-art catalysts, solvents or co-catalysts were not required. Pyridine and ammonia were used as probe molecules to estimate the type and density of acid sites in fresh and reused ZIF-8 catalysts. DRIFT spectroscopy of adsorbed pyridine revealed the presence of both Bronsted (B) and Lewis (L) acid sites. The B-sites have nearly vanished in the case of recycled ZIF-8 catalysts. The simultaneous presence of both the acid sites and the nitrogen basic moieties from the imidazole linker in ZIF-8 promoted the adsorption of the CO2 on the solid surface and its further conversion to the cyclic carbonate. The ZIF-8 catalysts could be recycled and reused without significant loss in catalytic activity. Published by Elsevier B.V.

}, keywords = {CO2 conversion, cyclic carbonates, Styrene carbonate, Zeolitic imidazolate frameworks, ZIF-8}, issn = {1566-7367}, doi = {10.1016/j.catcom.2012.12.003}, author = {Zhu, Minqi and Srinivas, Darbha and Bhogeswararao, Seemala and Ratnasamy, Paul and Carreon, Moises A.} } @article { ISI:000329886900036, title = {Cu(II) conjugation along the transformation of a vitamin K-3 derivative to a dinaphthoquinone methide radical}, journal = {New Journal of Chemistry}, volume = {38}, number = {1}, year = {2014}, month = {JAN}, pages = {277-284}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

1,1{\textquoteright}-Methide-bi-vitamin K-3 (B) has been isolated as a dinaphthoquinone methide radical (DNQM) by the transformation of 1-imino(acetylhydrazino)-vitamin K-3 (A). The transformation follows a biomimetic activation pathway mediated via Cu(II) ion catalyzed oxidative coupling. Single crystal X-ray and electron spin resonance (ESR) experiments combined with density functional calculations elucidate the {\textquoteleft}{\textquoteleft}resonance structure{\textquoteright}{\textquoteright} of the DNQM radical (B). Fluorescence investigations reveal that DNQM facilitates interaction with the cysteine residue. As compared to the parent substrate, B shows a depletion in the level of GSH, triggering apoptosis in HeLa cells.

}, issn = {1144-0546}, doi = {10.1039/c3nj00783a}, author = {Badave, Kirti D. and Patil, Shalaka S. and Khan, Ayesha A. and Srinivas, Darbha and Butcher, Raymond J. and Gonnade, Rajesh G. and Puranik, Vedavati G. and Pinjari, Rahul V. and Gejji, Shridhar P. and Rane, Sandhya Y.} }