School of Chemistry

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    1,2-Cyclopropanated sugars \b reactions and synthetic utility
    (University of Hyderabad, 1997-09-20) Ramana, C.V.
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    1,2-Diketones from alkylbromides using na < inf > 2 < /inf > fe(co) < inf > 4 < /inf > /cucl system
    ( 1992-02-25) Davasagayaraj, Arockiasamy ; Periasamy, Mariappan
    Reaction of alkylbromides with Na2Fe(CO)4 under carbon monoxide atmosphere followed by CuCl treatment gives the corresponding 1,2-diketones in 70-90% yields. © 1992.
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    1,2-Ene dithiolate bridged diiron carbonyl-phosphine and -phosphite complexes in relevance to the active site of [FeFe]-hydrogenases: Synthesis, characterization and electrocatalysis
    ( 2012-10-15) Durgaprasad, Gummadi ; Das, Samar K.
    A series of binuclear {Fe IFe I} complexes, such as, [Fe 2{μ-6,7-qdt}(CO) 6], [Fe 2{μ-diph-6,7- qdt}(CO) 6] and [Fe 2{μ-btdt}(CO) 6] have recently been reported by us. These complexes have now been examined to explore structural, electronic and electrochemical effects on substituting one or two CO group(s) with other donor ligands, e.g., phosphine and phosphite ligands. Mono-phosphine substituted compounds [Fe 2{μ-6,7-qdt}(CO) 5PPh 3] (1), [Fe 2{μ-diph-6,7-qdt}(CO) 5PPh 3] (2) and [Fe 2{μ-btdt}(CO) 5PPh 3] (7) are synthesized by the reactions of [Fe 2{μ-6,7-qdt}(CO) 6], [Fe 2{μ-diph-6,7-qdt} (CO) 6] and [Fe 2{μ-btdt}(CO) 6] respectively with PPh 3 in the presence of Me 3NO. Interestingly, treatment of [Fe 2{μ-6,7-qdt}(CO) 6], [Fe 2{μ-diph-6,7-qdt}(CO) 6] and [Fe 2{μ-btdt} (CO) 6] with controlled amount of P(OEt) 3 affords the mono-substituted phosphite derivatives [Fe 2{μ-6,7-qdt}(CO) 5P(OEt) 3] (3), [Fe 2{μ-diph-6,7-qdt}(CO) 5P(OEt) 3] (4), [Fe 2{μ-btdt}(CO) 5 P(OEt) 3] (8) respectively. The same reaction with an excess amount of P(OEt) 3 affords the di-substituted phosphite derivatives [Fe 2{μ-6,7-qdt}(CO) 4{P(OEt) 3} 2] (5), [Fe 2{μ-diph-6,7-qdt}(CO) 4{P(OEt) 3} 2] (6) and [Fe 2{μ-btdt}(CO) 4{P(OEt) 3} 2] (9) correspondingly. These new complexes 1-9 have been characterized by IR, 1H, 13C, and 31P{ 1H} NMR and mass spectroscopy including elemental analysis. The solid state structures for all compounds have been determined by single-crystal X-ray structure analyses. The electrochemistry of 1-9 was performed by cyclic voltammetry to evaluate the effects of phosphine and phosphite ligands on the reduction potentials of the all carbonyl di-iron model complexes [Fe 2{μ-6,7-qdt}(CO) 6], [Fe 2{μ-diph-6,7-qdt}(CO) 6] and [Fe 2{μ-btdt} (CO) 6]. The electrocatalytic activities of model complexes 7-9 toward proton reduction of a strong acid p-HOTs have been described. © 2012 Elsevier B.V. All rights reserved.
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    1,2-Phenylene-Incorporated Smallest Expanded Calix[4]pyrrole via One-Step Synthesis of Tetrapyrrane: A Fluorescent Host for Fluoride Ion
    ( 2021-08-06) Kumar, B. Sathish ; Chandra, Brijesh ; Jovan Jose, K. V. ; Panda, Pradeepta K.
    Synthesis of tetrapyrrane 8 from acetone and pyrrole via one-step condensation was achieved for the first time along with a much-improved yield of the tripyrrane 9. Diborylation of the tetrapyrrane and subsequent "1 + 1"cyclocoupling with 1,2-diiodobenzene following the Suzuki protocol generated novel o-phenylene incorporated macrocycle belonging to the smallest meso-expanded calix[4]pyrrole family. The latter macrocycle displays exclusive turn-on fluorescence sensing of fluoride ion upon complexation via a unique partial cone conformation supported by DFT analysis in acetonitrile solvent.
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    1,2-Shift in the anodic oxidation of aromatic compounds
    ( 1979-01-01) Bhat, Gajanan A. ; Periasamy, Mariappan ; Vivekananda Bhatt, M.
    The 1,2-shift observed during oxidation of organic substrates can arise by involvement of cation radicals. © 1979.
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    1-Benzopyran-4(4H)-ones as novel activated alkenes in the Baylis-Hillman reaction: A simple and facile synthesis of indolizine-fused-chromones
    ( 2003-06-02) Basavaiah, Deevi ; Jaganmohan Rao, Anumolu
    1-Benzopyran-4(4H)-one derivatives have been successfully employed as novel activated alkenes in the Baylis-Hillman coupling with heteroaromatic-aldehydes, nitrobenzaldehydes and isatin-derivatives and the corresponding adducts, derived from pyridine-2-carboxaldehyde, have been transformed into a novel indolizine-fused-chromone framework. © 2003 Elsevier Science Ltd. All rights reserved.
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    1-Dimensional and 2-dimensional coordination network structures in the Ba-Ce-dipicH < inf > 2 < /inf > system (dipicH < inf > 2 < /inf > = dipicolinic acid)
    ( 2005-08-25) Prasad, T. K. ; Sailaja, S. ; Rajasekharan, M. V.
    Reaction of dipicolinic acid with ammonium ceric nitrate and barium chloride produces, by self-assembly, three coordination polymers having similar stoichiometry but very different network structures. The structure of Ba(dipicH2)(OH2)4Ce(dipic)3· 4.6H2O (1) is built up of 1-D alternating chains of nine-coordinate Ce and Ba polyhedra, each having tricapped trigonal prismatic geometry. The structure of Ba(OH2)6Ce(dipic)3 (2), wherein a chain of nine-coordinate aquo-Ba polyhedra is threaded through the channel formed by a trigonal arrangement of the Ce(dipic)32- anions, is analogous to that of SrCl2·6H2O· Ba(OH2) 4Ce(dipic)3·2H2O (3), a polymorph of 2 (formally its hydrate isomer), exhibits a layered network in which Ce and Ba coordination polyhedra are linked by dipic ligands to form a corrugated sheet structure and may be considered as a metal-organic analog of the PbO lattice. © 2005 Elsevier Ltd. All rights reserved.
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    10,10′-Dibromo-9,9′-bianthryl
    ( 2003-11-01) Sarkar, Moloy ; Samanta, Anunay
    In the title compound, C28H16Br2, the two anthryl moieties are almost perpendicular to each other; the dihedral angles between the anthryl planes are 89.42 (9) and 82.36 (7)° in the two independent molecules, one of which lies on a crystallographic twofold rotation axis. An interesting feature of the crystal structure is the presence of C - H⋯π interactions. © 2003 International Union of Crystallography Printed in Great Britain - all rights reserved.
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    10,15-Bis (ethoxycarbonyl)-5-(4-methoxycarbonylphenyl) B(III)subchlorin: A photosensitizer with high singlet oxygen producing efficiency
    ( 2021-10-01) Bhat, Ishfaq A. ; Soman, Rahul ; Chandra, Brijesh ; Sahoo, Sameeta ; Thaltiri, Vikranth ; Panda, Pradeepta K.
    A novel A2B-type B(III)subchlorin has been synthesized for the first time in two ways possessing two different ester moieties upon macrocyclic periphery from meso-diethoxycarbonyl tripyrrane. Its photophysical and electrochemical properties have been explored. Introduction of the third meso-substituent resulted in the synthesis of the B(III)subchlorin as the major product with the formation of minor oxidized B(III)subporphyrin analogue. This subchlorin derivative was found to generate singlet oxygen much efficiently with quantum yield (φΔ) 0.88.
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    10-fold enhancement in light-driven water splitting using niobium oxynitride microcone array films
    ( 2016-07-01) Shaheen, Basamat S. ; Hafez, Ahmed M. ; Murali, Banavoth ; Kirmani, Ahmad R. ; Amassian, Aram ; Mohammed, Omar F. ; Allam, Nageh K.
    We demonstrate, for the first time, the synthesis of highly ordered niobium oxynitride microcones as an attractive class of materials for visible-light-driven water splitting. As revealed by the ultraviolet photoelectron spectroscopy (UPS), photoelectrochemical and transient photocurrent measurements, the microcones showed enhanced performance (~1000% compared to mesoporous niobium oxide) as photoanodes for water splitting with remarkable stability and visible light activity.
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    12-membered macrocycles containing ditelluroxane and selenotelluroxane units
    ( 2012-01-01) Srungavruksham, Nagarjuna Kumar ; Baskar, Viswanathan
    The reaction of benzeneseleninic acid with bis(p-methoxyphenyl)tellurium dihalide [halide = Cl (1), Br (2)] afforded colorless crystals in moderate yield. Single-crystal X-ray diffraction revealed the formation of 12-membered macrocycles [(p-MeO-C6H4)2Te(μ-O)(μ- PhSeO2)(μ4-X)]2 [X = Cl (1), Br (2)] where the halogen atoms, which are stabilized by Te-X interactions, cap the macrocycle on both sides. The reaction of NaI with 1 afforded the iodo-capped macrocycle [(p-MeO-C6H4)2Te(μ-O)(μ-PhSeO 2)(μ4-I)]2 (3) in good yield. In the solid-state structures of 1-3, the alignment of the phenyl group on Se changes with respect to the macrocycle. Macrocycle 3 shows rare Se-π interactions, which lead to the formation of a supramolecular polymeric network. Further reaction of methaneseleninic acid with bis(p-methoxyphenyl)tellurium dichloride in methanol in the presence of triethylamine afforded a 12-membered macrocycle [(p-MeO-C6H4)2Te(μ-O)(μ-MeSeO 2)(μ4-Cl)]2 (4), which is structurally similar to 1-3.
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    17,17-Ethylenedioxyandrost-4-ene-3,6-dione and 17,17-ethylenedioxyandrosta-1,4-diene-3,6-dione
    ( 1998-12-15) Anthony, Addlagatta ; Jaskolski, Mariusz ; Nangia, Ashwini ; Desiraju, Gautam R.
    The crystal structures of 17,17-ethylenedioxyandrost-4-ene-3,6-dione, C21H28O4, and 17,17-ethylenedioxyandrosta-1,4-diene-3,6-dione, C21H26O4, intermediates in the synthesis of heteroandrogenic aromatase inhibitors, have been determined. Both structures are stabilized by C-H⋯O hydrogen bonds, highlighting the importance of weak interactions in influencing packing motifs in general and the conformation of the flexible dioxolane ring in particular.
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    1:2 and 1:1 Ag(I)-isonicotinamide coordination compounds: Five-fold interpenetrated CdSO < inf > 4 < /inf > network and the first example of (pyridine)N-Ag-O(amide) bonds
    ( 2004-03-01) Bhogala, Balakrishna R. ; Thallapally, Praveen K. ; Nangia, Ashwini
    On the basis of acid-pyridine and acid-amide hydrogen bond synthons in dicarboxylic acid-isonicotinamide complexes and proton/silver mimicry in carboxylic acids, isonicotinamide was reacted with AgBF4 to afford different coordination compounds. The crystal structure of [Ag(C 5H4NCONH2)2] [BF4] 1 has linear tapes of Npyridyl-Ag-Npyridyl (180.0°) connected via N-H⋯O and N-H⋯F hydrogen bonds in square nets with CdSO4 topology. The 16 x 17 Åvoids eschew 5-fold interpenetration of identical nets. [Ag(C5H4NCONH 2)] [BF4] 2 provides the first occurrence of near linear Npyridyl-Ag-Oamide bonds (165.4°). The similarity in motifs of carboxylic acid and Ag(I) is extended to heterosynthons for crystal engineering.
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    1D water chain stabilized by meso-expanded calix[4]pyrrole
    ( 2014-10-07) Sathish Kumar, B. ; Panda, Pradeepta K.
    A new core expanded calix[4]pyrrole is reported, in which the opposite bridging sp3-carbons are replaced by ethylene moieties. This macrocycle forms a unique helical pattern and binds to two water molecules, forming an infinite 1D chain synergistically stabilized through hydrogen bonding with the two outwardly projected pyrrolic NHs of the calixpyrrole. This journal is © the Partner Organisations 2014.
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    (1R, 2R)-2-nitroxycyclohexan-1-ol: First example of a cyclohexyl based chiral auxiliary with nitroxy function as diastereoface discriminating group
    ( 1996-01-01) Basavaiah, Deevi ; Pandiaraju, Subramanian ; Bakthadoss, Manickam ; Muthukumaran, Kannan
    Application of nitroxy substituent as diastereoface discriminating group in a cyclohexyl based chiral auxiliary has been described.Copyright © 1996 Elsevier Science Ltd.
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    2,2′-Biphenyl (cyclohexylamino)phosphonate: A hydrogen-bonded dimer
    ( 1999-01-01) Muthiah, C. ; Swamy, K. C.Kumara
    The structure of the title compound, C18H20NO3P, reveals a hydrogen-bonding interaction between the NH group and the phosphoryl-O atom, resulting in a dimer; no interaction of the O atoms of the seven-membered 1,3,2-dioxaphosphepine ring with the NH proton is found. © 1999 International Union of Crystallography Printed in Great Britain - all rights reserved.
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    2,2′-Diselenobis(4,4-diphenylcyclohexa-2,5-dienone)
    ( 2000-01-01) Senthil Kumar, V. S. ; Nangia, Ashwini
    The title compound, C36H26O2Se2, displays crystallographic twofold symmetry. The packing involves corrugated linear ribbons mediated through C-H⋯O and C-H⋯Se interactions. The ribbons are connected through C-H⋯π interactions.
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    2,4,6-Tris(4-nitrophenoxy)-1,3,5-triazine: A hexagonal host framework stabilised by the NO < inf > 2 < /inf > -trimer supramolecular synthon
    ( 2002-05-07) Jetti, Ram K.R. ; Thallapally, Praveen K. ; Nangia, Ashwini ; Lam, Chi Keung ; Mak, Thomas C.W.
    The title molecule forms a honeycomb network of molecular and nitro-trimer synthons with guest species included in the hexagonal voids.
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    2,4,6-tris[bis(1H-tetrazol-5-yl)amino]-1,3,5-triazine as a nitrogen-rich material
    ( 2017-06-01) Rao, Muddamarri Hanumantha ; Ghule, Vikas D. ; Muralidharan, Krishnamurthi
    Abstract: This paper describes the synthesis, characterization and energetic properties of tetrazole and triazine-based thermally stable, insensitive nitrogen-rich high energy density materials of N, N’, N”-(1,3,5-triazine-2,4,6-triyl) tris(N-cyanocyanamide) [1] and 2,4,6-tris[bis(1H-tetrazol-5-yl)amino]-1,3,5-triazine [2]. The compound 2 is the first example for compounds having six tetrazole units on a triazine ring. Graphical Abstract : Synopsis Synthesis, characterization and energetic properties of the molecule, N 2, N 2, N 4, N 4, N 6, N 6-hexa(1H-tetrazol-5-yl)-1,3,5-triazine-2,4,6-triamine (2) having 79% nitrogen content with high HOF value is discussed. The high nitrogen content associated with high positive heat of formation of the compound 2 underline the structural importance of six tetrazole groups in a molecule. [Figure not available: see fulltext.]
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    2,6-Dibenzoyl-1,4-benzoquinone
    ( 1997-11-15) Biradha, Kumar ; Zaworotko, Michael J. ; Nangia, Ashwini ; Desiraju, Gautam R.
    In contrast to the stacking characteristic of quinones, the title compound, C20Q12O4, forms a two-dimensional network of C-H⋯O hydrogen bonds. The molecule has an unsymmetrical butterfly shape with the two benzoyl O atoms lying out of the plane of the quinonoid ring. The unusual conformation is a result of the crystal packing and the numerous weak hydrogen bonds.