On October 13, 2021, the historical group of the Royal Society of Chemistry organised a symposium celebrating ~150 years of the history of (molecular) chirality. We met for the first time in person for more than 18 months and were treated to a splendid and diverse program about the subject. The first speaker was Professor John Steeds from Bristol, talking about the early history of light and the discovery of its polarisation.
In the previous blog post, I looked at the metadata records registered with DataCite for some chemical computational modelling files as published in three different repositories. Here I take it one stage further, by looking at how searches of the DataCite metadata store for three particular values of the metadata associated with this dataset compare.
The number of repositories which accept research data across a wide spectrum of disciplines is on the up. Here I report the results of conducting an experiment in which chemical modelling data was deposited in six such repositories and comparing the richness of the metadata describing the essential properties of the six depositions. The repositories are as follows: Figshare as a repository dates from 2012.
You might have noticed if you have read any of my posts here is that many of them have been accompanied since 2006 by supporting calculations, normally based on density functional theory (DFT) and these calculations are accompanied by a persistent identifier pointer ‡ to a data repository publication.
An earlier post investigated large anomeric effects involving two oxygen atoms attached to a common carbon atom. A variation is to replace one oxygen by a nitrogen atom, as in N-C-O. Shown below is a scatter plot of the two distances to the common carbon atom derived from crystal structures. You can see some entries for which the C-O bond length is shorter than normal and the C-N distance very much longer than normal;
The homologous hydrocarbon series R 4 C is known for R=Me as neopentane and for R=Et as 3,3-diethylpentane. The next homologue, R=* i *Pr bis(3,3-isopropyl)-2,4-dimethylpentane is also a known molecule[cite]10.1002/1521-3773(20010105)40:1%3C180::AID-ANIE180%3E3.3.CO;2-B[/cite] for which a crystal structure has been reported (DOI: https://doi.org/10.5517/cc4wvnh). The final member of the series, R= t butyl is unknown.
Whilst I was discussing the future of scientific publication in the last post, a debate was happening behind the scenes regarding the small molecule cyclopropenylidene. This is the smallest known molecule displaying π-aromaticity, but its high reactivity means that it is unlikely to be isolated in the condensed phase.
In 2011, I suggested that the standard monolith that is the conventional scientific article could be broken down into two separate, but interlinked components, being the story or narrative of the article and the data on which the story is based.
In the earlier post on the topic of anomeric effects, I identified a number of outliers associated with large differences in the lengths of two carbon-oxygen bonds sharing a common carbon atom. Here is another of these outliers (MUZZIS[cite]10.1107/S2056989016002899[/cite]) which shows equally unusual properties.
In another post, a discussion arose about whether it might be possible to trap cyclopropenylidene to form a small molecule with a large dipole moment. Doing so assumes that cyclopropenylidene has a sufficiently long lifetime to so react, before it does so with itself to e.g. dimerise.
