January 23rd, 2018
Another occasional conference report (day 1). So why is one about “persistent identifiers” important, and particularly to the chemistry domain?
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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.
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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
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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.
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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.
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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.
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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.‡
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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.
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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.‡
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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 »
December 8th, 2017
An article with the title shown above in part recently appeared.[cite]10.1038/s41598-017-02687-z[/cite] Given the apparent similarity of HF1- to CH3F1- and CH3F2-, the latter of which I introduced on this blog previously, I thought it of interest to apply my analysis to HF1-.
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December 7th, 2017
FAIR data is increasingly accepted as a description of what research data should aspire to; Findable, Accessible, Inter-operable and Re-usable, with Context added by rich metadata (and also that it should be Open). But there are two sides to data, one of which is the raw data emerging from say an instrument or software simulations and the other in which some kind of model is applied to produce semi- or even fully processed/interpreted data. Here I illustrate a new example of how both kinds of data can be made to co-exist.
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Tags: computing, Context, data, Data management, Information, Knowledge, Raw data, software simulations, Technology/Internet
Posted in Chemical IT, crystal_structure_mining | No Comments »