Chemical SciencesWordPress

Henry Rzepa's Blog

Henry Rzepa's Blog
Chemistry with a twist
Home PageAtom Feed
language
Interesting ChemistryAntiaromaticityAromaticityBaird's RuleConjugated SystemChemical Sciences
Published

There is emerging interest in cyclic conjugated molecules that happen to have triplet spin states and which might be expected to follow a 4n rule for aromaticity. The simplest such system would be the triplet state of cyclobutadiene, for which a non or anti-aromatic singlet state is always found to be lower in energy.

Chemical ITAcademic PublishingAcrobatArticlesChemical DiscoveriesChemical Sciences
Published

The traditional structure of the research article has been honed and perfected for over 350 years by its custodians, the publishers of scientific journals. Nowadays, for some journals at least, it might be viewed as much as a profit centre as the perfected mechanism for scientific communication.

Interesting ChemistryChemical KineticsChemical ReactionChemistryDeuteriumChemical Sciences
Published

Five years back, I speculated about the mechanism of the epoxidation of ethene by a peracid, concluding that kinetic isotope effects provided interesting evidence that this mechanism is highly asynchronous and involves a so-called “hidden intermediate”. Here I revisit this reaction in which a small change is applied to the atoms involved.

HistoricalAlan DronsfieldAlizarinAnthraquinone DyesArt MaterialsChemical Sciences
Published

The Royal Society of Chemistry historical group (of which I am a member) organises two or three one day meetings a year. Yesterday the October meeting covered (amongst other themes) the fascinating history of madder and its approximately synthetic equivalent alizarin.

Interesting ChemistryAbsolute ConfigurationBiochemistryBulk SolutionsChemical TransformationsChemical Sciences
Published

I am exploring the fascinating diverse facets of a recently published laboratory experiment for undergraduate students. Previously I looked at a possible mechanistic route for the reaction between an enal (a conjugated aldehyde-alkene) and benzyl chloride catalysed by base and a chiral amine, followed by the use of NMR coupling constants to assign relative stereochemistries.