2,089 publications from this institution
Hollow nanotubes of zirconia as well as of yttria-stabilized zirconia are successfully prepared by first coating the carbon nanotubes appropriately with the oxidic material and then burning off the carbon of the template.
Properties of materials determined by their size are indeed fascinating and form the basis of the emerging area of nanoscience. In this article, we examine the size dependent electronic structure and properties of nanocrystals of semiconductors and metals to illustrate this aspect. We then discuss the chemical reactivity of metal nanocrystals which is strongly dependent on the size not only because of the large surface area but also a result of the significantly different electronic structure of the small nanocrystals. Nanoscale catalysis of gold exemplifies this feature. Size also plays a role in the assembly of nanocrystals into crystalline arrays. While we owe the beginnings of size-dependent chemistry to the early studies of colloids, recent findings have added a new dimension to the subject.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAn investigation of well-characterized small gold clusters by photoelectron spectroscopy, tunneling spectroscopy, and cognate techniquesC. N. R. Rao, V. Vijayakrishnan, Hemantkumar N. Aiyer, G. U. Kulkarni, and G. N. SubbannaCite this: J. Phys. Chem. 1993, 97, 43, 11157–11160Publication Date (Print):October 1, 1993Publication History Published online1 May 2002Published inissue 1 October 1993https://doi.org/10.1021/j100145a006RIGHTS & PERMISSIONSArticle Views296Altmetric-Citations53LEARN 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 InReddit PDF (2 MB) Get e-Alerts
Graphenes with varying number of layers can be synthesized by different strategies. Thus, single-layer graphene is obtained by the reduction of single layer graphene oxide, CVD and other methods besides micromechanical cleavage. Few-layer graphenes are prepared by the conversion of nanodiamond, arcdischarge of graphite and other means. We briefly present the various methods of synthesis and the nature of graphenes obtained. We then discuss the various properties of graphenes. The remarkable property of graphene of quenching fluorescence of aromatic molecules is shown to be associated with photo-induced electron transfer, on the basis of fluorescence decay and time-resolved transient absorption spectroscopic measurements. The interaction of electron donor and acceptor molecules with few-layer graphene samples has been discussed. Decoration of metal nano-particles on graphene sheets and the resulting changes in electronic structure are examined. Few-layer graphenes exhibit ferromagnetic features along with antiferromagnetic properties, independent of the method of preparation. Graphene-like MoS 2 and WS 2 have been prepared by chemical methods, and the materials are characterized by electron microscopy, atomic force microscopy (AFM) and other methods. Boron nitride analogues of graphene have been obtained by a simple chemical procedure starting with boric acid and urea and have been characterized by various techniques.
Photoacoustic spectroscopy is found to be a useful technique for determining the acidity of zeolites. The acidity so determined correlates well with temperature programmed desorption studies of ammonia and product distribution.
Quantitative thermodynamic data on the hydrogen bonding of tetra-n-heptylammonium iodide with various hydroxy compounds have been obtained. The importance of hydrogen bonding in explaining the solvent effects on the C.T.T.S. transition of the iodide ion has been pointed out. Some aspects of the electronic transitions of the iodide ion have also been discussed.
Organic molecules may accept an extra electron to form radical anions, R+, or give up an electron by ionization to form radical cations, R+. Some of the radical ions are relatively stable in their ground states in solution phase and can be readily characterized by spectroscopic methods. Electron spin resonance spectroscopy provides an ideal tool for the study of the unshared electron in these radical ions. Most radical ions are intensely colored and give characteristic absorption bands in the electronic spectra. Further, electronic spectroscopy is one of the few tools available for the study of the dianions, which are generally diamagnetic. Electronic spectroscopy is used not merely for the characterization of the ionic species in solution but also for the study of the chemical equilibria involving various kinds of ionic species.
No abstract is provided for this article.
Properties of materials determined by their size are indeed fascinating and form the basis of the emerging area of nanoscience. In this article, we examine the size dependent electronic structure and properties of nanocrystals of semiconductors and metals to illustrate this aspect. We then discuss the chemical reactivity of metal nanocrystals which is strongly dependent on the size not only because of the large surface area but also a result of the significantly different electronic structure of the small nanocrystals. Nanoscale catalysis of gold exemplifies this feature. Size also plays a role in the assembly of nanocrystals into crystalline arrays. While we owe the beginnings of size-dependent chemistry to the early studies of colloids, recent findings have added a new dimension to the subject.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
