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?[cite]10.1039/C6CC06395K[/cite] Here I explore the difference between two different and very simple approaches to predicting its reactivity. 
Molecule orbitals as indicators of reactivity: bromoallene.
September 1st, 2016Journal innovations – the next step is augmented reality?
August 17th, 2016In the previous post, I noted that a chemistry publisher is about to repeat an earlier experiment in serving pre-prints of journal articles. It would be fair to suggest that following the first great period of journal innovation, the boom in rapid publication “camera-ready” articles in the 1960s, the next period of rapid innovation started around 1994 driven by the uptake of the World-Wide-Web. The CLIC project[cite]10.1080/13614579509516846[/cite] aimed to embed additional data-based components into the online presentation of the journal Chem Communications, taking the form of pop-up interactive 3D molecular models and spectra. The Internet Journal of Chemistry was designed from scratch to take advantage of this new medium.[cite]10.1080/00987913.2000.10764578[/cite] Here I take a look at one recent experiment in innovation which incorporates “augmented reality”.[cite]10.1055/s-0035-1562579[/cite]
A periodic table for anomeric centres, this time with quantified interactions.
August 8th, 2016The 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. Here I quantify the effect, by selecting the test molecule MeO-X-OMe, where X is of two types:
A periodic table for anomeric centres.
August 6th, 2016In 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.
Stereoelectronic effects galore: bis(trifluoromethyl)trioxide.
August 4th, 2016Here 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.
Anomeric effects at carbon involving lone pairs originating from one or two nitrogens.
July 8th, 2016The previous post looked at anomeric effects set up on centres such as B, Si or P, and involving two oxygen groups attached to these atoms. Here I vary the attached groups to include either one or two nitrogen atoms.[cite]10.14469/hpc/936[/cite]
Anomeric effects at boron, silicon and phosphorus.
July 1st, 2016
The anomeric effect occurs at 4-coordinate (sp3) carbon centres carrying two oxygen substituents and involves an alignment of a lone electron pair on one oxygen with the adjacent C-O σ*-bond of the other oxygen. Here I explore whether other centres can exhibit the phenomenon. I start with 4-coordinate boron, using the crystal structure search definition below (along with R < 0.1, no disorder, no errors).[cite]10.14469/hpc/696[/cite]
How does an OH or NH group approach an aromatic ring to hydrogen bond with its π-face?
June 22nd, 2016I previously used data mining of crystal structures to explore the directing influence of substituents on aromatic and heteroaromatic rings. Here I explore, quite literally, a different angle to the hydrogen bonding interactions between a benzene ring and OH or NH groups.