February 9th, 2018
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.
Read the rest of this entry »
Tags: City: London, Country: United Kingdom, Royal Horticultural Society, Wildflower
Posted in Interesting chemistry | 1 Comment »
February 3rd, 2018
The topic of open citations was presented at the PIDapalooza conference and represents a third component in the increasing corpus of open scientific information.
Read the rest of this entry »
Tags: Academic publishing, Applied linguistics, article processing charge, British National Corpus, chemical stories, cited author, Corpus linguistics, David Shotton, Entertainment/Culture, Linguistics, Open access, Quotation, RDF, social media, Texas A&M–Corpus Christi Islanders women's basketball
Posted in Chemical IT | 2 Comments »
January 23rd, 2018
Another occasional conference report (day 1). So why is one about “persistent identifiers” important, and particularly to the chemistry domain?
Read the rest of this entry »
Tags: Academic publishing, Andy Mabbett, Digital Object Identifier, Identifiers, Imperial College, Index, Information science, Johanna McEntyre, Knowledge, Mark Hahnel, ORCiD, Persistent identifier, Publishing, Quotation, researcher, Scholarly communication, SciCrunch, search engines, Technical communication, Technology/Internet, Tom Gillespie
Posted in Chemical IT | 1 Comment »
January 14th, 2018
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. Apparently not, so here are a few details.
Read the rest of this entry »
Tags: Chemistry, Derek Lowe, Deuterated drug, Drug, drug design, FDA, Food and Drug Administration, Haloperidol, Health, Health/Medical/Pharmaceuticals, HTC HD2 Smartphone, metabolic products, Pharmaceutical industry, Pharmacy, physico-chemical profiles, United States Public Health Service
Posted in General | No Comments »
January 13th, 2018
I discussed the molecule the molecule CH3F2- a while back. It was a very rare computed example of a system where the added two electrons populate the higher valence shells known as Rydberg orbitals as an alternative to populating the C-F antibonding σ-orbital to produce CH3– and F–. The net result was the creation of a weak C-F “hyperbond”, in which the C-F region has an inner conventional bond, with an outer “sheath” encircling the first bond. But this system very easily dissociates to CH3– and F– and is hardly a viable candidate for experimental detection. In an effort to “tune” this effect to see if a better candidate for such detection might be found, I tried CMe3F2-. Here is its story.
Read the rest of this entry »
Tags: Antibonding molecular orbital, candidate for experimental detection, chemical bonding, chemical shift, Chemistry, metal, Molecular orbital, Nature
Posted in Hypervalency | 2 Comments »
January 6th, 2018
The title here is from an article on metalenses[cite]10.1021/acs.nanolett.6b01897[/cite] which caught my eye.
Read the rest of this entry »
Tags: Biochemistry, Biology, Chemistry, Chirality, Circular dichroism, Nature, Pharmacology, Polarization, spectroscopy, Stereochemistry, Ultraviolet, Vibrational circular dichroism
Posted in Interesting chemistry | No Comments »
December 26th, 2017
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.
Read the rest of this entry »
Tags: chemical bonding, Chemistry, diazo, Diazo compounds, Diazomethane, diazomethane-like systems, Functional groups, Hypervalent molecule, Molecular geometry, Organic chemistry, Recollects
Posted in Hypervalency | 8 Comments »
December 23rd, 2017
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. Here I explore the effect of substituting diazomethane with cyano and nitro groups.‡
Read the rest of this entry »
Tags: candidate for hypervalent carbon, chemical bonding, Hypervalent molecule, Molecular geometry
Posted in Hypervalency, Interesting chemistry | No Comments »
December 23rd, 2017
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.
Read the rest of this entry »
Tags: kinetic energy density
Posted in Hypervalency, Interesting chemistry | No Comments »
December 17th, 2017
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! So here I take a look at this intriguingly simple little molecule.‡
Read the rest of this entry »
Tags: Alkalide, Ammonium, Anions, Atomic physics, Chemistry, electron gas, energy, free-electron gas, Jahn-Teller, kinetic energy density, Matter, Nitrogen, potential energy surface, search query
Posted in Hypervalency | 2 Comments »