Can a single C–H⋯F–C hydrogen bond make a difference? Assessing the H⋯F bond strength from 2-D 1H-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.