V. Balaji

This paper presents the joint effect of strain- and doping-induced band gap change in Sn1−xMnxO (0 ≤ x ≤ 0.05) nanoparticles. In addition, an effort was made to understand the effect of Mn doping on the structural and optical properties of SnO2. X-ray diffraction analysis showed a tetragonal structure and the unit cell volume decreased slightly with Mn4+ content. The Mn:SnO2 are spherical shaped particles with a size ranging from 7.7 to 13.8 nm as calculated by transmission electron microscopy, Scherrer's formula and Willamson–Hall plot. X-ray photoelectron spectroscopy showed clear evidence for tetragonal coordinated high-spin Mn4+ ions occupying the lattice sites of Sn4+ in the SnO2 host. Electron energy loss spectroscopy further confirmed composition and oxidation states of Sn4+ and Mn4+ ions. Manganese doping increased the band gap of SnO2 from 4 eV to 4.40 eV with Mn4+ concentration. Variation in band gap energy was attributed to the increasing lattice strain with Mn content and the charge transfer transitions between Mn4+ ions and conduction/valence bands of SnO2. Three photoluminescence emission bands observed at 320, 360 and 380 nm, when excited at 250 nm, proved Mn:SnO2 to exhibit good optical emission and to have potential application in nanoscale optoelectronic devices.

The photoaffinity reagent 8-[(4-azidophenyl)-methoxy]-1-tritiomethyl-2, 3-dimethylimidazo-[1,2-alpha]pyridinium iodide ([3H]mDAZIP) has been synthesized and used to photoinactivate and label purified hog gastric H+,K(+)-ATPase. The specific (K(+)-sensitive) components of both photoinactivation and labeling showed dependences on inhibitor concentration consistent with covalent modification at an extracytoplasmic site of reversible K(+)-competitive binding in the dark. The maximum amount of specific labeling (1.2 nmol/mg) was similar to the number of phosphorylation sites measured (1.0 +/- 0.14 nmol/mg). Specific labeling was distributed 76% on the alpha chain, 18% on the beta chain, and 6% on undefined peptides. Various digestions with trypsin, protease V8, and thermolysin were employed to fragment the labeled enzyme. Gasphase sequencing of the radioactive peptides identified the major site of specific labeling to be within a region where only two stretches of amino acids (Leu105 to Ile126 and Leu139 to Phe155, designated H1 and H2, respectively) are predicted to span the membrane. This in turn suggested that the labeling site was located within or close to the proposed loop between them (Gln127 to Asn138). A computer-driven energy minimization protocol yielded a loop structure to which SCH 28080 (the parent structure of [3H]mDAZIP) could be docked. Conversely, modeling of the corresponding region of Na+,K(+)-ATPase (a homologous enzyme with much lower affinity for SCH 28080) yielded no apparent binding site. Similarities in the inhibition of H+,K(+)-ATPase by SCH 28080 and of Na+,K(+)-ATPase by ouabain lead to the hypothesis that, in each case, inhibitor binding to E2-P is associated with an increase in the hydrophobicity of the environment of the loop between H1 and H2.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMatrix isolation of silacyclopentadienes: UV-visible and IR spectra and photochemical interconversionValery N. Khabashesku, V. Balaji, Sergei E. Boganov, Oleg M. Nefedov, and Josef MichlCite this: J. Am. Chem. Soc. 1994, 116, 1, 320–329Publication Date (Print):January 1, 1994Publication History Published online1 May 2002Published inissue 1 January 1994https://pubs.acs.org/doi/10.1021/ja00080a037https://doi.org/10.1021/ja00080a037research-articleACS PublicationsRequest reuse permissionsArticle Views516Altmetric-Citations81LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStudy of long-range .pi.*,.pi.* interactions in rigid molecules by electron transmission spectroscopyV. Balaji, L. Ng, K. D. Jordan, M. N. Paddon-Row, and H. K. PatneyCite this: J. Am. Chem. Soc. 1987, 109, 23, 6957–6969Publication Date (Print):November 1, 1987Publication History Published online1 May 2002Published inissue 1 November 1987https://pubs.acs.org/doi/10.1021/ja00257a010https://doi.org/10.1021/ja00257a010research-articleACS PublicationsRequest reuse permissionsArticle Views329Altmetric-Citations71LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts