CH-Anion versus anion-π interactions in the crystal and in solution of pentafluorobenzyl phosphonium salts

Abstract

A series of phosphonium salts with pentafluorobenzyl substituents have been synthesized and were investigated in the crystal as well as in solution. The solid state structures of 1a, 1b and 2d reveal the presence of anion-π as well as CH-anion interactions. The two attractive, yet competitive forces seem to act in concert and a directing effect of the CH interaction on the relative position between anion and π-system is observed. The search for anion-π interactions in solution failed. Only CH-anion interactions proved to be important in solution.

Anion‐π Interaction: An Influential Force in Solid State Molecular Microstructures

“…Our earlier studies showed the appropriateness of (pentafluorobenzyl)phosphonium salts as target molecules for the study of anion‐π interactions in the solid state 15. In addition to previously described structures of pentafluorobenzyl phoshonium halides, we herein report the corresponding tetrafluoroborate ( 3c ), hexafluorophosphate ( 3d ), and hydrosulfate ( 3e ) structures.…”

“…Triphenyl(pentafluorobenzyl)phosphonium Bromide 3a: Synthesized according to a previously described procedure 15…”

Rational Topological Design for Fluorescence Enhancement upon Aggregation of Distyrylfuran Derivatives

“…[12c] Triphenyl(pentafluorobenzyl)phosphonium bromide was synthesized by treating triphenylphosphine with pentafluorobenzyl bromide according to al iterature method. [20] 2-Phenylacetonitrile and 2-perfluorophenylacetonitrile were obtained from commercial sources and used as received.…”

Pentafluorophenyl salicylamine receptors in anion–π interaction studies

“…First attempts to find some relevance of anion -p interactions in solution by studying pentafluorobenzyl phosphonium salts show no evidence for this intermolecular force in chloroform (13).…”