More inspiration from tutorials. In a lecture on organic aromaticity, the 4n+2/4n Hückel rule was introduced (in fact, neither rule appears to have actually been coined in this form by Hückel himself!). The simplest examples are respectively the cyclopropenyl cation and anion. The former has 2 π-electrons exhibiting cyclic delocalisation, and the 4n+2 (n=0) rule predicts aromaticity. Accordingly, all three C-C distances are the same (1.363Å).
Archive for December 7th, 2010
(anti)aromaticity avoided: a tutorial example
Tuesday, December 7th, 2010Tags:energy, free energy, Huckel, Interesting chemistry, Pretty straight forward, Tutorial material
Posted in Interesting chemistry | 12 Comments »
Data-round-tripping: wherein the future?
Tuesday, December 7th, 2010Moving (chemical) data around in a manner which allows its (automated) use in whichever context it finds itself must be a holy grail for all scientists and chemists. I posted earlier on the fragile nature of molecular diagrams making the journey between the editing program used to create them (say ChemDraw) and the Word processor used to place them into a context (say Microsoft office), via an intermediate storage area known as the clipboard. The round trip between the Macintosh (OS X) versions of these programs had been broken a little while, but it is now fixed! A small victory. This blog reports what happened when such a Mac-created Word document is sent to someone using Microsoft Windows as an OS (or vice versa).
Tags:Android, cellular telephone, chemical, chemical information, Chemical IT, content carrier, HTML, iPad, JPEG, Mac OS X, Macintosh, Microsoft, Microsoft Windows, opendata, operating systems, search engines, Web browser, word processor, XML
Posted in Chemical IT | No Comments »