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Henry Rzepa's Blog

Henry Rzepa's Blog
Chemistry with a twist
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Interesting ChemistryAutomated Stochastic Search ProcedureFree EnergyMetalScientistCiencias QuímicasInglés
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The (hopefully tongue-in-cheek) title Mindless chemistry was given to an article reporting an automated stochastic search procedure for locating all possible minima with a given composition using high-level quantum mechanical calculations. “Many new structures, often with nonintuitive geometries, were found”. Well, another approach is to follow unexpected hunches.

Interesting Chemistry3-dimethylcyclobutadieneBlog ServerCalixareneChemical ThinkingCiencias QuímicasInglés
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I have mentioned Lewis a number of times in these posts; his suggestion of the shared electron covalent bond still underpins much chemical thinking. Take for example mechanistic speculations on the course of a reaction, a very common indulgence in almost all articles reporting such, and largely based on informed  arrow pushing.

Interesting ChemistryBasic BoronTutorial MaterialCiencias QuímicasInglés
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I have often heard the question posed “how much of chemistry has been discovered?” Another might be “has most of chemistry, like low-hanging fruit, already been picked?“. Well, time and time again, one comes across examples which are only a simple diagram or so away from what might be found in any introductory chemistry text, […]

GeneralArtistChemical DiagramChemistDNA DuplexCiencias QuímicasInglés
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In his famous lecture in 1959, C. P. Snow wrote about the breakdown in communications between the “two cultures” of modern society — the sciences and the humanities (arts). That was then. This is now, and the occasion of my visit to a spectacular “city of arts and sciences complex” in Europe.

Chemical ITInteresting Chemistry3D GraphicsAntimalarialAntimalarial Pharmaceutical MoleculeCiencias QuímicasInglés
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In 1986 or so, molecular modelling came of age. Richard Counts, who ran an organisation called QCPE (here I had already submitted several of the program codes I had worked on) had a few years before contacted me to ask for my help with his Roadshow.

Interesting ChemistryAntarafacialCycloadditionEnergyFernandezCiencias QuímicasInglés
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Steve Bachrach has blogged on the reaction shown below. If it were a pericyclic cycloaddition, both new bonds would form simultaneously, as shown with the indicated arrow pushing. Ten electrons would be involved, and in theory, the transition state would have 4n+2 aromaticity.

Chemical ITChemical ShiftsChemistry Department Computer NetworkControllerDirectorCiencias QuímicasInglés
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Computers and I go back a while (44 years to be precise), and it struck me (with some horror) that I have been around them for ~62% of the modern computing era (Babbage notwithstanding, ~1940 is normally taken as the start of the modern computing era). So indulge me whilst I record this perspective from […]

HypervalencyELFQTAIMCiencias QuímicasInglés
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A little while ago, I speculated (blogs are good for that sort of thing) about hexavalent carbon, and noted how one often needs to make (retrospectively) obvious connections between two different areas of chemistry. That post has attracted a number of comments in the two years its been up, along the lines: what about carboranes?