Last year, I showed photos of wildflower meadows in west London close to where we live, evolving as the seasons changed. Today we hear the announcement that London itself is set be declared the world’s first National Park City in 2019. What is a park city you may ask? It draws on the principles of National Parks such as the Peak District, the New Forest, or the South Downs in the UK, but in a city setting.

The topic of open citations was presented at the PIDapalooza conference and represents a third component in the increasing corpus of open scientific information. David Shotton gave us an update on  Citations as First Class data objects – Citation Identifiers and introduced (me) to the blog where he discusses this topic.

Another occasional conference report (day 1). So why is one about “persistent identifiers” important, and particularly to the chemistry domain? The PID most familiar to most chemists is the DOI (digital object identifier). In fact there are many; some 60 types have been collected by ORCID (themselves purveyors of researcher identifiers). They sometimes even have different names;

I don’t normally write about the pharmaceutical industry, but I was intrigued by several posts by Derek Lowe (who does cover this area) on the topic of creating new drugs by deuterating existing ones. Thus he covered the first deuterated drug receiving FDA approval last year, having first reviewed the concept back in 2009. So when someone introduced me to sila-haloperidol , I checked to see if Derek had written about it.

I discussed the molecule the molecule CH3F2- a while back.

The title here is from an article on metalenses[cite]10.1021/acs.nanolett.6b01897[/cite] which caught my eye. Metalenses are planar and optically thin layers which can be manufactured using a single-step lithographic process. This contrasts with traditional lenses that are not flat and where the optical properties result from very accurately engineered curvatures, which in turn are expensive to manufacture.

Recollect the suggestion that diazomethane has hypervalent character[cite]10.1039/C5SC02076J[/cite]. When I looked into this, I came to the conclusion that it probably was mildly hypervalent, but on carbon and not nitrogen. Here I try some variations with substituents to see what light if any this casts.

In the previous post, I referred to a recently published review on hypervalency[cite]10.1039/C5SC02076J[/cite] which introduced a very simple way (the valence electron equivalent γ) of quantifying the effect. Diazomethane was cited as one example of a small molecule exhibiting hypervalency (on nitrogen) by this measure.

A recently published review on hypervalency[cite]10.1039/C5SC02076J[/cite] introduced a very simple way of quantifying the effect. One of the molecules which was suggested to be hypervalent using this method was diazomethane. Here I take a closer look.

Alkalides are anionic alkali compounds containing e.g. sodide (Na–), kalide (K–), rubidide (Rb–) or caeside (Cs–). Around 90 examples can be found in the Cambridge structure database (see DOI: 10.14469/hpc/3453  for the search query and results). So what about the ammonium analogue, ammonide (NH4–)? A quick search of Scifinder drew a blank!

An article with the title shown above in part recently appeared.[cite]10.1038/s41598-017-02687-z[/cite] Given the apparent similarity of HF ^1- to CH ₃ F ^1- and CH ₃ F ^2- , the latter of which I introduced on this blog previously, I thought it of interest to apply my analysis to HF ^1- . The authors[cite]10.1038/s41598-017-02687-z[/cite] conclude that “ the F atom of HF ⁻