Archive for September, 2009
Wednesday, September 30th, 2009
In the previous two posts, I noted the recent suggestion of how a stable frozen SN2 transition state might be made. This is characterised by a central carbon with five coordinated ligands. The original suggestion included two astatine atoms as ligands (X=At), but in my post I suggested an alternative which would have five carbon ligands instead (X=cyclopentadienyl anion).
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Tags:Ge, Hypervalency, Interesting chemistry
Posted in Hypervalency, Interesting chemistry | 3 Comments »
Tuesday, September 22nd, 2009
The bimolecular nucleophilic substitution reaction at saturated carbon is an icon of organic chemistry, and is better known by its mechanistic label, SN2. It is normally a slow reaction, with half lives often measured in hours. This implies a significant barrier to reaction (~15-20 kcal/mol) for the transition state, shown below (X is normally both a good nucleophile and a good nucleofuge/leaving group, such as halide, cyanide, etc. Y can have a wide variety of forms).
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Tags:ACS, computational chemist, Ethan L. Fisher, Hypervalency, Interesting chemistry, potential systems, Salt Lake City, Steve Bachrach, Tristan H. Lambert, United States
Posted in Hypervalency, Interesting chemistry | 3 Comments »
Friday, September 18th, 2009
Chemistry can be very focussed nowadays. This especially applies to target-driven synthesis, where the objective is to make a specified molecule, in perhaps as an original manner as possible. A welcome, but not always essential aspect of such syntheses is the discovery of new chemistry. In this blog, I will suggest that the focus on the target can mean that interesting chemistry can get over-looked (or if observed, not fully exploited in subsequent publications). Taking a synthesis-oriented publication at (almost) random entitled Synthesis of 1-Oxadecalins from Anisole Promoted by Tungsten (DOI: 10.1021/ja803605m) which appeared in 2008, the following molecule appears as one of the (many) intermediates.
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Tags:Chemical IT, conformational analysis, Interesting chemistry, pseudo
Posted in Chemical IT, Interesting chemistry | 7 Comments »
Monday, September 7th, 2009
The science journal is generally acknowledged as first appearing around 1665 with the Philosophical Transactions of the Royal Society in London and (simultaneously) the French Academy of Sciences in Paris. By the turn of the millennium, around 10,000 science and medical journals were estimated to exist. By then, the Web had been around for a decade, and most journals had responded to this new medium by re-inventing themselves for it. For most part, they adopted a format which emulated paper (Acrobat), with a few embellishments (such as making the text fully searchable) and then used the Web to deliver this new reformulation of the journal. Otherwise, Robert Hooke would have easily recognized the medium he helped found in the 17th century.
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Tags:A. I. Magee, A. Jana, A. P. Dove, Acrobat, American Chemical Society, aqueous solution, Balasundaram Lavan, C. S. M Allan, C. Wentrup, Chemical IT, chemical plugin, Chemoinformatics, Colorado, D. A. Widdowson, D. C. Braddock, D. J. Williams, D. R. Carbery, D. Scheschkewitz, Dalton Trans, digital Acrobat, E. H. Smith, E. M. Barreiro, E. W. Tate, Enhance Chemical Electronic Publishing, Extrusion Reactions, F. Diederich, F. Santoro, French Academy, G. Siligardi, G. Stammler, Ge, H. S. Rzepa, HTML, I. Omlor, I. Pavlakos, Interchange Apical, Interesting chemistry, Ion-Pair Mechanisms, β-diketiminate metal alkoxides, J. Clarke, J. Jana, J. L. Arbour, J. Lorenzo Alonso-Gómez, J. P. White, J. R. Arendorf, journal editor, K. K. (Mimi) Hii, K. P. Tellmann, King, Kuok Hii, L. A. Adrio, L. Johannissen, Lewis Base Catalyst, M. E. Cass, M. Hii, M. J. Cowley, M. J. Fuchter, M. J. Harvey, M. J. Humphries, M. J. Porter, M. Jakt, M. R. Crittall, M. Ritzefeld, M. Weimar, Marshall, Michael Wright, N. Berova, N. Harada, N. J. Mason, N. Mason, N. Masumoto, O. Casher, opendata, P. G. Pringle, P. Jutzi, P. Lo, P. Seiler, Paris, Peter Murray-Rust, polymerization, Porter, printing, R. B. Moreno, R. M. Williams, R. Schleyer, R. Wilhelm, Rappaport, RDF, representative, Robert Hooke, Royal Society in London, S. Díez-González, S. Lai, S. M. Allan, S. Martin-Santamaria, Sonsoles Martên-Santamarêa, Square Pyramidal Molecules, T. Lanyon-Hogg, the Philosophical Transactions of the Royal Society, V, V(III) Co, V. C. Gibson, V. Huch, V. W. Pike, W. B. Motherwell, Web Application, Web Table, XML, XSLT, Ya-Pei Lo
Posted in Chemical IT, Interesting chemistry | 6 Comments »