A few years back, I did a post about the Pirkle reagent[cite]10.1039/c39910000765[/cite] and the unusual π-facial hydrogen bonding structure[cite]10.1039/P29940000703[/cite] 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.
Posts Tagged ‘Centroid’
Ammonium tetraphenylborate and the mystery of its π-facial hydrogen bonding.
Friday, March 10th, 2017How does an OH or NH group approach an aromatic ring to hydrogen bond with its π-face?
Wednesday, June 22nd, 2016I 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.