Some 13 years ago, I speculated about the longevity of the type of science communication then (and still now) represented by Blogs. I noted one new project called ArchivePress that was looking into providing solutions equivalent to what scientific journals have done for some 350 years of science communication. The link to ArchivePress no longer works, but details of the project can still be found here.

The schematic representation of a chemical reaction mechanism is often drawn using a palette of arrows connecting or annotating the various molecular structures involved. These can be selected from a chemical arrows palette, taken for this purpose from the commonly used structure drawing program Chemdraw.

The Swern oxidation[cite]10.1016/0040-4020(78)80197-5[/cite] is a class of “activated” dimethyl sulfoxide (DMSO) reaction in which the active species is a chlorodimethylsulfonium chloride salt.

Respiratory pigments are metalloproteins that transport O ₂ , the best known being the bright red/crimson coloured hemoglobin in human blood. The colour derives from Fe ²⁺ at the core of a tetraporphyrin ring. But less well known is blue blood , and here the colour derives from an oxyhemocyanin unit based on Cu ¹⁺ (the de-oxy form is colourless) rather than iron.

I have variously talked about persistent identifiers on this blog. These largely take the form of DOIs (Digital object identifiers), and here they relate to either journal articles or datasets associated with either the article or the blog post or both. Other disciplines, particularly the earth sciences, have long used persistent identifiers (PIDs) to identify physical objects rather than digital ones.

Sometimes, the properties of a molecule are predicted long before it is synthesised. One such is diberyllocene. I first encountered a related molecule, beryllocene itself, many moons ago.[cite]10.1021/ja00471a020[/cite] This was unusual because unlike the original metallocenes, the metal atom was not symmetrically disposed between the two cyclopentadienyl faces.

This is a venerable organic reaction, which curiously I have not previously covered here. First described in 1859, its nature was only properly elucidated in 1873. It is a member of a class of reaction I have previously named “solvolytically assisted pericyclic”, or “perisolvolytic”. Here I explore some of the subtle stereoelectronic effects observed for this apparently simple reaction. It applies to a class of molecule known as 1,2-diols.

This editorial from Nature[cite]10.1038/d41586-023-01612-x[/cite] is a timely reminder of the importance of data.

Some time ago in 2010, I showed a chemical problem I used to set during university entrance interviews. It was all about pattern recognition and how one can develop a hypothesis based on this. In that instance, it involved recognising that a cyclic molecule which appeared to have the cyclohexatriene benzene-aromatic pattern 1 was in fact a trimer of carbon dioxide.

One of the important aspects of chemical reaction mechanisms is the order in which things happen. More specifically, the order in which bonds make or break when there are more than two involved in undertaking a reaction.