Can a single C–H⋯F–C hydrogen bond make a difference? Assessing the H⋯F bond strength from 2-D¹H-¹⁹F CP/MAS NMR

Abstract

Contrary to common belief a single C–H⋯F–C contact in [(η5-C5H5)Pd(C6F5)(PPh3)] is strong enough to pair two independent molecules and render them crystallographically different as suggested by its strongest 1H–19F dipole–dipole coupling in a 2-D CP/MAS PILGRIM NMR experiment together with solid state 1-D 19F{1H} and 2-D 19F RFDR NMR spectroscopy – thereby proving the power of 2-D solid-state NMR for assessing the strength of supramolecular contacts.