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[cite]10.1038/nchem.2716[/cite] 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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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 9th, 2017
The title refers to an upcoming symposium on the topic on 22-24 May, 2017. I quote here some of the issues tabled for discussion:
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Tags: Contact Details, Social Media & Networking, Symposium, Technology/Internet, Will technology
Posted in Chemical IT, General | 1 Comment »
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,[cite]10.3390/molecules22040549[/cite] 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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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[cite]10.1126/science.aal1619[/cite] reports a molecular knot with the remarkable number of eight crossings.
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Tags: Cheminformatics, Chemistry, Drug discovery, Education, π-systems, Matter, Molecule, Nature, spectroscopy, Structure validation
Posted in Interesting chemistry | 3 Comments »
January 2nd, 2017
Here is an inside peek at another one of Derek Lowe’s 250 milestones in chemistry, the polymorphism of Ritonavir.[cite]10.1023/A:1011052932607[/cite] The story in a nutshell concerns one of a pharma company’s worst nightmares; a drug which has been successfully brought to market unexpectedly “changes” after a few years on market to a less effective form (or to use the drug term, formulation). This can happen via a phenomenon known as polymorphism, where the crystalline structure of a molecule can have more than one form.[cite]10.1021/ar00052a005[/cite],[cite]10.1002/anie.201410356[/cite],[cite]10.1039/D1SC06074K[/cite] In this case, form I was formulated into soluble tablets for oral intake. During later manufacturing, a new less-soluble form appeared and “within weeks this new polymorph began to appear throughout both the bulk drug and formulation areas“[cite]10.1023/A:1011052932607[/cite]
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Tags: Carbamates, Chemistry, Derek Lowe, free energy, high energy process, High-energy rotations, higher energy, higher energy s-trans form, hydrogen bonding network, later manufacturing, Lipid polymorphism, low energy conformational effects, low energy rotations, lower energy rotation, Peek, Polymorphism, Protease inhibitors, Ritonavir, RTT, SN, Software engineering, Thiazoles, Ureas
Posted in Interesting chemistry | No Comments »
December 31st, 2016
My holiday reading has been Derek Lowe’s excellent Chemistry Book setting out 250 milestones in chemistry, organised by year. An entry for 1920 entitled hydrogen bonding seemed worth exploring in more detail here.
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Tags: 10.1021, aqueous solution, Chemical bond, chemical bonding, Chemistry, Derek Lowe, Hydrogen, Hydrogen bond, Intermolecular forces, Lowe's, Nature, Supramolecular chemistry
Posted in Historical | 2 Comments »
December 24th, 2016
The previous posts produced discussion about the dipole moments of highly polar molecules. Here to produce some reference points for further discussion I look at the dipole moment of glycine, the classic zwitterion (an internal ion-pair).
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Tags: aqueous solution, Chemical polarity, Chemistry, dielectric, Dipole, Electric dipole moment, Electromagnetism, Magnetism, Moment, Nature, Physical quantities, Physics, Potential theory, zwitterion
Posted in crystal_structure_mining, Interesting chemistry | 1 Comment »