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.
The Chemistry Department at Imperial College London. A history, 1845-2000.
February 10th, 2017The 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.
Forming a stabilized m-benzyne.
January 20th, 2017The 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.
Braiding a molecular knot with eight crossings.
January 20th, 2017This 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.
Ritonavir: a look at a famous example of conformational polymorphism.
January 2nd, 2017Here 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]
The “hydrogen bond”; its early history.
December 31st, 2016My 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.
The dipole moments of highly polar molecules: glycine zwitterion.
December 24th, 2016The 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).
Forking “The most polar neutral compound synthesized” into m-benzyne.
December 21st, 2016A project fork is defined (in computing) as creating a distinct and separate strand from an existing (coding) project. Here I apply the principle to the polar azulene 4 explored in an earlier post, taking m-benzyne as a lower homologue of azulene as my starting point.