Is asking a question such as “what is the smallest angle subtended at a chain of three connected 4-coordinate carbon atoms” just seeking another chemical record, or could it unearth interesting chemistry?
Archive for October, 2016
The smallest C-C-C angle?
Monday, October 31st, 2016An inorganic double helix: SnIP.
Sunday, October 16th, 2016After sixty years of searching, the first non-templated double helical carbon-free inorganic molecular structure has been reported.[1] That is so neat that I thought to load the 3D coordinates here for you to interact with and then to explore the prospect of using these coordinates to add some value with e.g. some chiroptical calculations.
References
- D. Pfister, K. Schäfer, C. Ott, B. Gerke, R. Pöttgen, O. Janka, M. Baumgartner, A. Efimova, A. Hohmann, P. Schmidt, S. Venkatachalam, L. van Wüllen, U. Schürmann, L. Kienle, V. Duppel, E. Parzinger, B. Miller, J. Becker, A. Holleitner, R. Weihrich, and T. Nilges, "Inorganic Double Helices in Semiconducting SnIP", Advanced Materials, vol. 28, pp. 9783-9791, 2016. http://dx.doi.org/10.1002/adma.201603135
Catenated atoms and groups.
Thursday, October 13th, 2016Chemists are as fond of records as any, although I doubt you will find many chemical ones in the Guinness world records list. Polytriangulanes chase how many cyclopropyl 3-rings can be joined via a vertex. Steve Bachrach on his blog reports some recent work by Peter Schreiner and colleagues[1] and the record for catenation of such rings appears to be 15. This led me to think about some other common atoms and groups. Here I have searched for crystal structures only; there may be examples of course for which no such data has been reported.
References
- W.D. Allen, H. Quanz, and P.R. Schreiner, "Polytriangulane", Journal of Chemical Theory and Computation, vol. 12, pp. 4707-4716, 2016. http://dx.doi.org/10.1021/acs.jctc.6b00669
σ or π nucleophilic reactivity of imines? A mechanistic reality check using substituents.
Sunday, October 9th, 2016Previously, a mechanistic twist to the oxidation of imines using peracid had emerged. Time to see how substituents respond to this mechanism.