Posts Tagged ‘Centroid’
Friday, March 10th, 2017
A few years back, I did a post about the Pirkle reagent[1] and the unusual π-facial hydrogen bonding structure[2] it exhibits. For the Pirkle reagent, this bonding manifests as a close contact between the acidic OH hydrogen and the edge of a phenyl ring; the hydrogen bond is off-centre from the middle of the aryl ring. Here I update the topic, with a new search of the CSD (Cambridge structure database), but this time looking at the positional preference of that bond and whether it is on or off-centre.
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References
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H.S. Rzepa, M.L. Webb, A.M.Z. Slawin, and D.J. Williams, "? Facial hydrogen bonding in the chiral resolving agent (S)-2,2,2-trifluoro-1-(9-anthryl)ethanol and its racemic modification", Journal of the Chemical Society, Chemical Communications, pp. 765, 1991. http://dx.doi.org/10.1039/c39910000765
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H.S. Rzepa, M.H. Smith, and M.L. Webb, "A crystallographic AM1 and PM3 SCF-MO investigation of strong OH ⋯π-alkene and alkyne hydrogen bonding interactions", J. Chem. Soc., Perkin Trans. 2, pp. 703-707, 1994. http://dx.doi.org/10.1039/P29940000703
Tags:Ammonia, Ammonium, aromaticity, Cations, Centroid, chemical bonding, Chemistry, Hydrogen bond, Phenyl group
Posted in crystal_structure_mining | No Comments »
Wednesday, June 22nd, 2016
I previously used data mining of crystal structures to explore the directing influence of substituents on aromatic and heteroaromatic rings. Here I explore, quite literally, a different angle to the hydrogen bonding interactions between a benzene ring and OH or NH groups.
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Tags:10.1021, 10.1107, 10.5517, aromaticity, benzene, Centroid, chemical bonding, Chemical IT, data mining, Functional groups, Hydrogen bond, Physical organic chemistry, Pyridine, Simple aromatic rings, Supramolecular chemistry
Posted in crystal_structure_mining | 3 Comments »
Saturday, April 2nd, 2016
A celebration of the life and work of the great chemist Paul von R. Schleyer was held this week in Erlangen, Germany. There were many fantastic talks given by some great chemists describing fascinating chemistry. Here I highlight the presentation given by Andy Streitwieser on the topic of organolithium chemistry, also a great interest of Schleyer's over the years. I single this talk out since I hope it illustrates why people still get together in person to talk about science.
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Tags:Centroid, chemical effect, chemical insights, chemical interpretation, Chemical IT, City: Erlangen, Country: Germany, Degree of a continuous mapping, Ferrocene, Hydrogen bond, individual search definition, Interesting chemistry, metal, overall search collection, Streitwieser, terminal H-positions, Torsion, X-ray
Posted in crystal_structure_mining | 6 Comments »