@article { ISI:000227346300059, title = {Unusual monodentate binding mode of 2,2 {\textquoteleft}-dipyridylamine (L) in isomeric trans(acac)(2)Ru-II(L)2, trans-[(acac)(2)Ru-III(L)(2)]ClO4, and cis-(acac)(2)Ru-II(L)(2) (acac = acetylacetonate). Synthesis, structures, and spectroscopic, electrochemical, and magn}, journal = {Inorganic Chemistry}, volume = {44}, number = {5}, year = {2005}, month = {MAR}, pages = {1571-1579}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

{The reaction of cis-Ru(acac)(2)(CH3CN)(2) (acac = acetylacetonate) with 2,2{\textquoteright}-dipyridylamine (L) in ethanolic medium resulted in facile one-pot synthesis of stable [(acac)(2)Ru-III(L)]ClO4 ([1]ClO4), trans-[(acac)(2)Ru-II(L)2] (2), trans[(acac)(2)Ru-III(L)(2)[ClO4 ([2]ClO4), and cis-[(acac)(2)Ru-II(L)(2)] (3). The bivalent congener 1 was generated via electrochemical reduction Of [1]ClO4. Although in [1](+) the dipyridylamine ligand (L) is bonded to the metal ion in usual bidentate fashion, in 2/[2](+) and 3, the unusual monodentate binding mode of L has been preferentially stabilized. Moreover, in 2/[2](+) and 3, two such monodentate L{\textquoteright}s have been oriented in the trans- and cis-configurations, respectively. The binding mode of L and the isomeric geometries of the complexes were established by their single-crystal X-ray structures. The redox stability of the Ru(II) state follows the order 1 \< 2 much less than 3. In contrast to the magnetic moment obtained for [1]ClO4

}, issn = {0020-1669}, doi = {10.1021/ic049219v}, author = {Kar, S. and Chanda, N. and Mobin, Shaikh M. and Urbanos, F. A. and Niemeyer, M. and Puranik, Vedavati G. and Jimenez-Aparicio, Reyes and Lahiri, Goutam Kumar} } @article { ISI:000248002800006, title = {Unprecedented two-dimensional polymeric [Zn(OOC-C6H4-COO)(2)](2_)(n)[+H3N-(CH2)(3)-NH(3])(+)n system bearing one-dimensional chain of zinc(II) bis(phthalate) dianions held by propane-1,3-diammonium cations: crystal structure, thermal and fluorescent pr}, journal = {Solid State Sciences}, volume = {9}, number = {6}, year = {2007}, month = {JUN}, pages = {491-495}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A novel zinc(II) phthalate compound, [Zn{C6H4(COO)(2)}(2)](n)(2-)[NH3-(CH2)(3)-NH3](n)(2+), 1 Which contains four different phthalate moieties coordinated to the Zn(II) ion through one each of their carboxyl ate moieties in a eta(1)-form and each phthalate moiety acting as a bridging unit with an overall tetrahedral geometry around the metal ion has been prepared and structurally characterized. The structure is unique in the sense that the dianionic moieties [Zn{C6H4(COO)(2)}(2)](2-) form an infinite one-dimensional network composed of 14-membered cyclic units interconnected in a way that they are disposed alternatively in almost perpendicular planes. The dicationic [NH3-(CH2)(3)-NH3](2+) units are seen to hold these one-dimensional chains by strong coulombic and hydrogen bond interaction, resulting in an infinite two-dimensional layered structure of 1. The compound is thermally stable up to 250 degrees C. Above this temperature it loses one equivalent of phthalate moiety along with the diammonium unit to yield Zn(II) phthalate. The thermodynamic and kinetic parameters associated with this process could be evaluated using Coats-Redfern equation which shows the activation energy Ea for the process as 305.0 kJ mol(-1), the frequency factor A as 1.49 x 10(11) s(-1) and the entropy change Delta S as -35.90 JK(-1) mol(-1). Fluorescent emission properties of 1 was studied by exciting the compound at 380 nm and also at 322 nm which were found to be the two lambda(max) corresponding to absorptions of the molecule. Interestingly, the compound gave same type of emission spectra showing a maximum around 444 nm on exciting at these two different wavelengths, indicating that the molecule comes to the first excited state from the higher excited state by a fast non-radiative process before it exhibits singlet emission to come to the ground state. (C) 2007 Elsevier Masson SAS. All rights reserved.

}, keywords = {1, 3-diammonium, cyclic chain, fluorescent emission, layered structure, propane, zinc(II) bis(phthalate) dianion, zinc-phthatate}, issn = {1293-2558}, doi = {10.1016/j.solidstatesciences.2007.04.009}, author = {Padmanabhan, A. and Joseph, K. C. and Puranik, Vedavati G. and Huang, Xiaoying and Li, Jing} } @article { ISI:000248376400006, title = {Unusual trisulphide linkage in bromine-thiourea reaction: crystal structure of formamidinium trisulphide complex with bromine}, journal = {Molecular Crystals and Liquid Crystals}, volume = {469}, year = {2007}, month = {SEP}, pages = {69+}, publisher = {TAYLOR \& FRANCIS LTD}, type = {Article}, address = {4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND}, abstract = {

{A new complex of formamidinium trisulphide with bromine has been synthesized. Single-crystal X-ray analysis of this compound revealed a novel trisulphide linkage in the formamidinium trisulphide moiety. The crystals belong to orthorhombic space group Fdd2 with a = 14.9119(15)

}, keywords = {bromine, crystal structure, formamidinium trisulphide, thiourea}, issn = {1542-1406}, doi = {10.1080/15421400701431265}, author = {Tol, Abhaya D. and Natu, Arun D. and Puranik, Vedavati G.} } @article { ISI:000255339600033, title = {Unexpected metal-promoted transformation yields an anthrylmethyl spiroanthracene}, journal = {Journal of Organic Chemistry}, volume = {73}, number = {9}, year = {2008}, month = {MAY}, pages = {3559-3561}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The isolation and characterization of an unusual spiroanthracene, from the reaction of bisdichlororuthenium(II)bi-pyridine dihydrate with 3-(9-anthrylmethyl)pentane-2,4-dione (AMPD), is reported. This metal-promoted formation of spiroanthracene has been obtained for the first time during the synthesis of metal complexes.

}, issn = {0022-3263}, doi = {10.1021/jo702284t}, author = {Kumbhar, Anupa A. and Kumbhar, Avinash S. and Puranik, Vedavati G.} } @article { ISI:000258293100059, title = {Use of enantiomerically pure 7-azabicyclo[2.2.1]heptan-2-ol as a chiral template for the synthesis of aminocyclitols}, journal = {Organic Letters}, volume = {10}, number = {16}, year = {2008}, month = {AUG}, pages = {3611-3614}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Using enantiopure 7-azabicyclo[2.2.1]heptane-2-ol, the synthesis of cis- as well as trans-2-aminocyclohexanols, dihydroconduramine E-1, and ent-conduramine F-1 has been described.

}, issn = {1523-7060}, doi = {10.1021/ol801381t}, author = {Pandey, Ganesh and Tiwari, Keshri Nath and Puranik, Vedavati G.} } @article { ISI:000253620600008, title = {Use of the pictet-spengler reaction for the synthesis of 1,4-disubstituted-1,2,3,4-tetrahydro-beta-carbolines and 1,4-disubstituted-beta-carbolines: formation of gamma-carbolines}, journal = {Tetrahedron}, volume = {64}, number = {8}, year = {2008}, month = {FEB}, pages = {1654-1662}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Microwave-assisted conjugate addition of indole on nitro-olefins furnished nitro compounds, which were reduced to tryptamines. Further, by using Pictet-Spengler condensation, new 1,4-disubstituted-1,2,3,4-tetrahydro-beta-carbolines were synthesized in diastereoselective manner. Dehydrogenation of the tetrahydro-beta-carbolines produced new 1,4-disubstituted-beta-carbolines. As a new observation, in some of the cases, Pictet-Spengler condensation and dehydrogenation gave two products, namely 1,4-disubstituted-beta-carbolines and 1,4-disubstituted-gamma-carbolines. A mechanism is proposed for this observation. (C) 2007 Elsevier Ltd. All rights reserved.

}, keywords = {1, 2, 3, 4-Disubstituted-1, 4-disubstituted-beta-carboline, 4-disubstituted-gamma-carboline, 4-tetrahydro-beta-carboline, 4-tetrahydro-gamma-carboline, Pictet-Spengler reaction}, issn = {0040-4020}, doi = {10.1016/j.tet.2007.12.008}, author = {Kusurkar, Radhika S. and Alkobati, Nabil A. H. and Gokule, Anita S. and Puranik, Vedavati G.} } @article { ISI:000300466900006, title = {Understanding the growth of micro and nano-crystalline AlN by thermal plasma process}, journal = {Journal of Crystal Growth}, volume = {339}, number = {1}, year = {2012}, month = {JAN}, pages = {36-45}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

We report the studies related to the growth of crystalline AlN in a DC thermal plasma reactor, operated by a transferred arc plasma torch. The reactor is capable of producing the nanoparticles of Al and AlN depending on the composition of the reacting gas. Al and AlN micro crystals are formed at the anode placed on the graphite and nano crystalline Al and AlN gets deposited on the inner surface of the plasma reactor. X-ray diffraction, Raman spectroscopy analysis, single crystal X-ray diffraction and TGA-DTA techniques are used to infer the purity of post process crystals as a hexagonal AlN. The average particle size using SEM was found to be around 30 mu m. The morphology of nanoparticles of Al and AlN, nucleated by gas phase condensation in a homogeneous medium were studied by transmission electron microscopy analysis. The particle ranged in size between 15 and 80 nm in diameter. The possible growth mechanism of crystalline AlN at the anode has been explained on the basis of non-equilibrium processes in the core of the plasma and steep temperature gradient near its periphery. The gas phase species of AlN and various constituent were computed using Murphy code based on minimization of free energy. The process provides 50\% yield of microcrystalline AlN and remaining of Al at anode and that of nanocrystalline h-AlN and c-Al collected from the walls of the chamber is about 33\% and 67\%, respectively. (C) 2011 Elsevier B.V. All rights reserved.

}, keywords = {Crystal morphology, Growth from high temperature solutions, Nitride, Semiconducting aluminum compound}, issn = {0022-0248}, doi = {10.1016/j.jcrysgro.2011.11.011}, author = {Kanhe, Nilesh S. and Nawale, Ashok B. and Gawade, Rupesh L. and Puranik, Vedavati G. and Bhoraskar, S. V. and Das, Asoka K. and Mathe, Vikas L.} } @article { ISI:000308414500020, title = {Unusual conformational similarity of two peptide folds featuring sulfonamide and carboxamide on the backbone}, journal = {Chemical Communications}, volume = {48}, number = {78}, year = {2012}, month = {AUG}, pages = {9747-9749}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Two folded peptides featuring carboxamide and sulfonamide at the core of the peptide fold have been shown to possess almost similar conformational features, despite the well-known fact that carboxamides and sulfonamides have strikingly different hydrogen-bonding and geometrical preferences.

}, issn = {1359-7345}, doi = {10.1039/c2cc34533a}, author = {Vijayadas, Kuruppanthara N. and Davis, Hilda C. and Kotmale, Amol S. and Gawade, Rupesh L. and Puranik, Vedavati G. and Rajamohanan, Pattuparambil R. and Sanjayan, Gangadhar J.} }