Chemical SciencesWordPress

Henry Rzepa's Blog

Henry Rzepa's Blog
Chemistry with a twist
Home PageAtom Feed
language
Curly ArrowsReaction MechanismActivation Free EnergyArrow PushingCurly ArrowChemical Sciences
Published

The concept of a “hidden intermediate” in a reaction pathway has been promoted by Dieter Cremer and much invoked on this blog. When I used this term in a recent article of ours, a referee tried to object, saying it was not in common use in chemistry. The term clearly has an image problem.

Interesting ChemistryAbove Energy DiagramEnergyEnergy TransferEnergy Transfer OccurringChemical Sciences
Published

The ultimate reduction in size for an engineer is to a single molecule. It’s been done for a car; now it has been reported for the pixel (picture-element).

Interesting ChemistryCambridgeChemical ReasonsMetalMetal SulfidesChemical Sciences
Published

I noted previously that some 8-ring cyclic compounds could exist in either a planar-aromatic or a non-planar-non-aromatic mode, the mode being determined by apparently quite small changes in a ring substituent. Hunting for other examples of such chemistry on the edge, I did a search of the Cambridge crystal database for metal sulfides.

Interesting ChemistryChemical Sciences
Published

The butterfly effect summarises how a small change to a system may result in very large and often unpredictable (chaotic) consequences. If the system is merely on the edge of chaos, the consequences are predictable, but nevertheless finely poised between e.g. two possible outcomes. Here I ask how a molecule might manifest such behaviour.

HypervalencyInteresting ChemistryChemical ShiftMetal AtomsMetal CarbideChemical Sciences
Published

A feature of a blog which is quite different from a journal article is how rapidly a topic might evolve. Thus I started a few days ago with the theme of dicarbon (C2), identifying a metal carbide that showed C2 as a ligand, but which also entrapped a single carbon in hexa-coordinated mode.

Chemical ITEnergy GapEnergy LevelsGoogleHarvardChemical Sciences
Published

The title of this post summarises the contents of a new molecular database: www.molecularspace.org and I picked up on it by following the post by Jan Jensen at www.compchemhighlights.org (a wonderful overlay journal that tracks recent interesting articles). The molecularspace project more formally is called “The Harvard Clean Energy Project: Large-scale computational screening and design of organic […]

HypervalencyInteresting ChemistryEnergyGas PhaseKnudsenChemical Sciences
Published

A comment made on the previous post on the topic of hexa-coordinate carbon cited an article entitled “Observation of hypervalent CLi6 by Knudsen-effusion mass spectrometry” by Kudo as a amongst the earliest of evidence that such species can exist (in the gas phase). It was a spectacular vindication of the earlier theoretical prediction, that such 6-coordinate […]