Compounds with O-O bonds often have weird properties. For example, artemisinin, which has some fascinating stereoelectronics. Here is another such, recently in the news and known as HMTD (hexamethylene triperoxide diamine). The crystal structure was reported some time ago and the article included an inspection of the computed wavefunction.

Nucleophiles are species that seek to react with an electron deficient centre by donating a lone or a π-bond pair of electrons. The ambident variety has two or more such possible sources in the same molecule, an example of which might be hydroxylamine or H2NOH.

I previously explored stabilized “carbenes” with the formal structures (R2N)2C:, concluding that perhaps the alternative ionic representation R2N+=C–NR2 might reflect their structures better.

To quote from Wikipedia: in chemistry, a carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons. The most ubiquitous type of carbene of recent times is the one shown below as 1, often referred to as a resonance stabilised or persistent carbene.

Bromoallene is a pretty simple molecule, with two non-equivalent double bonds. How might it react with an electrophile, say dimethyldioxirane (DMDO) to form an epoxide? Here I explore the difference between two different and very simple approaches to predicting its reactivity.

In the previous post, I noted that a chemistry publisher is about to repeat an earlier experiment in serving pre-prints of journal articles.

This week the ACS announced its intention to establish a “ChemRxiv preprint server to promote early research sharing“. This was first tried quite a few years ago, following the example of especially the physicists. As I recollect the experiment lasted about a year, attracted few submissions and even fewer of high quality.

The previous post contained an exploration of the anomeric effect as it occurs at an atom centre X for which the effect is manifest in crystal structures.

In the last few posts, I have explored the anomeric effect as it occurs at an atom centre X. Here I try to summarise the atoms for which the effect is manifest in crystal structures.

Here is a little molecule that can be said to be pretty electron rich. There are lots of lone pairs present, and not a few electron-deficient σ-bonds. I thought it might be fun to look at the stereoelectronic interactions set up in this little system.

In March, I posted from the ACS meeting in San Diego on the topic of Research data: Managing spectroscopy-NMR, and noted a talk by MestreLab Research on how a tool called Mpublish in the forthcoming release of their NMR analysis software Mestrenova could help. With that release now out, the opportunity arose to test the system.