March 5th, 2017
Cyclobutadiene is one of those small iconic molecules, the transience and instability of which was explained theoretically long before it was actually detected in 1965.[1] Given that instability, I was intrigued as to how many crystal structures might have been reported for this ring system, along with the rather more stable congener cyclo-octatetraene. Here is what I found.
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References
- L. Watts, J.D. Fitzpatrick, and R. Pettit, "Cyclobutadiene", Journal of the American Chemical Society, vol. 87, pp. 3253-3254, 1965. https://doi.org/10.1021/ja01092a049
Tags: antiaromaticity, Chemistry, cyclobutadiene, Instability, Nature, Physical organic chemistry, Physics, search query
Posted in crystal_structure_mining | 4 Comments »
February 15th, 2017
This post arose from a comment attached to the post on Na2He and relating to peculiar and rare topological features of the electron density in molecules called non-nuclear attractors. This set me thinking about other molecules that might exhibit this and one of these is shown below.
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Tags: Attractor, brief search, Chemistry, Electron, Electron density, Hydrogen, Molecule, Nature, Physics, Quantum chemistry
Posted in Interesting chemistry | 11 Comments »
February 14th, 2017
I analysed the bonding in chlorine trifluoride a few years back in terms of VSEPR theory. I noticed that several searches on this topic which led people to this post also included a query about the differences between it and the bromine analogue. For those who posed this question, here is an equivalent analysis.
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Tags: Bromine, Bromine trifluoride, Chemical elements, Chemistry, Chlorine, Fluorides, Halogens, Interhalogen compounds, Matter, Oxidizing agents, VSEPR theory
Posted in Interesting chemistry | 1 Comment »
February 11th, 2017
On February 6th I was alerted to this intriguing article[1] by a phone call, made 55 minutes before the article embargo was due to be released. Gizmodo wanted to know if I could provide an (almost)† instant‡ quote. After a few days, this report of a stable compound of helium and sodium still seems impressive to me and I now impart a few more thoughts here.
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References
- X. Dong, A.R. Oganov, A.F. Goncharov, E. Stavrou, S. Lobanov, G. Saleh, G. Qian, Q. Zhu, C. Gatti, V.L. Deringer, R. Dronskowski, X. Zhou, V.B. Prakapenka, Z. Konôpková, I.A. Popov, A.I. Boldyrev, and H. Wang, "A stable compound of helium and sodium at high pressure", Nature Chemistry, vol. 9, pp. 440-445, 2017. https://doi.org/10.1038/nchem.2716
Tags: 10.1038, Atom, Chemical elements, chemical phenomenon, Chemistry, Company: P. Acucar-CBD, Electride, Electron, Food Retail & Distribution - NEC, helium, Hydrogen, Matter, Oxygen, Physics, social media
Posted in Bond slam, crystal_structure_mining, Interesting chemistry | 11 Comments »
February 10th, 2017
The book of the title has recently appeared giving a rich and detailed view over 417 pages, four appendices and 24 pages of photographs of how a university chemistry department in the UK came into being in 1845 and its subsequent history of discoveries, Nobel prizes and much more. If you have ever wondered what goes on in an academic department, populated by and large by very bright and clever personalities and occasionally some highly eccentric ones, then go dip into this book.
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Tags: 2001-2050, Alfred Nobel, Bill Griffith, Country: United Kingdom, Education, Entertainment/Culture, Hannah Gay, Nobel Prize
Posted in Historical | 6 Comments »
February 2nd, 2017
Almost exactly 20 years ago, I started what can be regarded as the precursor to this blog. As part of a celebration of this anniversary,[1] I revisited the page to see whether any of it had withstood the test of time. Here I recount what I discovered.
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References
- P.W. May, S.A. Cotton, K. Harrison, and H.S. Rzepa, "The ‘Molecule of the Month’ Website—An Extraordinary Chemistry Educational Resource Online for over 20 Years", Molecules, vol. 22, pp. 549, 2017. https://doi.org/10.3390/molecules22040549
Tags: 10.5517, Advertising & Marketing - NEC, chemical context, chemical markup language, City: London, Commercial REITs - NEC, Company: Chime, Company: Eastman Kodak, Company: First Industrial, digital cameras, Digital Object Identifier, food additives, HTML, Imperial College, industrial strength HTML editor, Java, JavaScript, manufacturing factory, mauveine using molecular modelling software, Person Attributes, Photographic Equipment, Technology/Internet, validation tool, Web, web archaeology, web server, XML, year old Web pages
Posted in Chemical IT, Historical | 1 Comment »
January 20th, 2017
The story so far. Inspired by the report of the most polar neutral compound yet made, I suggested some candidates based on the azulene ring system that if made might be even more polar. This then led to considering a smaller π-analogue of azulene, m-benzyne. Here I ponder how a derivative of this molecule might be made, using computational profiling as one reality check.
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Tags: accessible activation free energy, Aryne, Azulenes, endothermic product
Posted in Interesting chemistry, reaction mechanism | 2 Comments »
January 20th, 2017
This is one of those posts of a molecule whose very structure is interesting enough to merit a picture and a 3D model. The study[1] reports a molecular knot with the remarkable number of eight crossings.
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References
- J.J. Danon, A. Krüger, D.A. Leigh, J. Lemonnier, A.J. Stephens, I.J. Vitorica-Yrezabal, and S.L. Woltering, "Braiding a molecular knot with eight crossings", Science, vol. 355, pp. 159-162, 2017. https://doi.org/10.1126/science.aal1619
Tags: Cheminformatics, Chemistry, Drug discovery, Education, π-systems, Matter, Molecule, Nature, spectroscopy, Structure validation
Posted in Interesting chemistry | 3 Comments »