Postagens de Rogue Scholar

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Publicados in Henry Rzepa's Blog

The upcoming ACS national meeting in San Diego has a CHED (chemical education division) session entitled Implementing Discovery-Based Research Experiences in Undergraduate Chemistry Courses. I had previously explored what I called extreme gauche effects in the molecule F-S-S-F. Here I take this a bit further to see what else can be discovered about molecules containing bonds between group 16 elements (QA= O, S, Se, Te).

Publicados in Henry Rzepa's Blog

Six years ago, I posted on the nature of a then recently reported[cite]10.1002/anie.200803859[/cite] Cr-Cr quintuple bond. The topic resurfaced as part of the discussion on a more recent post on NSF 3 , and a sub-topic on the nature of the higher order bonding in C 2 . The comment made a connection between that discussion and the Cr-Cr bond alluded to above.

Publicados in Henry Rzepa's Blog

Earlier I explored models for the heteroaromatic electrophilic protiodecarboxylation of an 3-substituted indole, focusing on the role of water as the proton transfer and delivery agent. Next, came models for both water and the general base catalysed ionization of indolinones.

Publicados in Henry Rzepa's Blog

The BBC TV quiz series Mastermind was first broadcast in the UK in 1972, the same time I was starting to investigate the mechanism of diazocoupling to substituted indoles as part of my Ph.D. researches. The BBC program became known for the catch phrase I've started so I'll finish; here I will try to follow this precept with the project I started then.

Publicados in Henry Rzepa's Blog

You might have noticed the occasional reference here to the upcoming centenary of the publication of Gilbert N. Lewis’ famous article entitled “ The atom and the molecule ”.[cite]10.1021/ja02261a002[/cite] A symposium exploring his scientific impact and legacy will be held in London on March 23, 2016, exactly 70 years to the day since his death. A list of the speakers and their titles is shown below;

Publicados in Henry Rzepa's Blog

The layout of floor 2 of the chemistry department here contains a number of small rooms which function as tutorial areas. Each has a (non-interactive) whiteboard used by students and tutors for, inter-alia , thought-showering. It was in one such room that I found myself with three colleagues this monday afternoon. We soon all sensed something not quite right about the room;

Publicados in Henry Rzepa's Blog

In answering tutorial problems, students often need skills in deciding how much time to spend on explaining what does not happen, as well as what does. Here I explore alternatives to the mechanism outlined in the previous post to see what computation has to say about what does (or might) not happen.

Publicados in Henry Rzepa's Blog

This reaction emerged a few years ago (thanks Alan!) as a tutorial problem in organic chemistry, in which students had to devise a mechanism for the reaction and use this to predict the stereochemical outcome at the two chiral centres indicated with *.  It originates in a brief report from R. B. Woodward’s group in 1973 describing a prostaglandin synthesis,[cite]10.1021/ja00801a066[/cite] the stereochemical outcome being crucial.

Publicados in Henry Rzepa's Blog

Steve Bachrach on his own blog has commented on a recent article[cite]10.1002/anie.201505934[/cite] discussing the structure of the trimer of fluoroethanol. Rather than the expected triangular form with three OH—O hydrogen bonds, the lowest energy form only had two such bonds, but it matched the microwave data much better. Here I explore this a bit more.