Posts Tagged ‘π-systems’

Braiding a molecular knot with eight crossings.

Friday, January 20th, 2017

This is one of those posts of a molecule whose very structure is interesting enough to merit a picture and a 3D model. The study[1] reports a molecular knot with the remarkable number of eight crossings.



  1. J.J. Danon, A. Krüger, D.A. Leigh, J. Lemonnier, A.J. Stephens, I.J. Vitorica-Yrezabal, and S.L. Woltering, "Braiding a molecular knot with eight crossings", Science, vol. 355, pp. 159-162, 2017.

NCI (non-covalent-interaction) analysis for some π-hydrogen bonded systems.

Tuesday, January 8th, 2013

In this post, I looked at some hydrogen bonds formed by interaction of a π-system with an acidic hydrogen. Unlike normal lone pair donors, π-systems can involve more than two electrons, most commonly four or six. Here I look at examples of both these higher-order donors.