Revisiting NMR through-space J(FF) spin-spin coupling constants for getting insight into proximate F---F interactions

J Phys Chem A. 2014 Jul 10;118(27):5068-75. doi: 10.1021/jp501929t. Epub 2014 Jun 30.

Abstract

At present times it is usual practice to mark biological compounds replacing an H for an F atom to study, by means of (19)F NMR spectroscopy, aspects such as binding sites and molecular folding features. This interesting methodology could nicely be improved if it is known how proximity interactions on the F atom affect its electronic structure as gauged through high-resolution (19)F NMR spectroscopy. This is the main aim of the present work and, to this end, differently substituted peri-difluoronaphthalenes are chosen as model systems. In such compounds are rationalized some interesting aspects of the diamagnetic and paramagnetic parts of the (19)F nuclear magnetic shielding tensor as well as the transmission mechanisms for the PSO and FC contributions to (4)JF1F8 indirect nuclear spin-spin coupling constants.