Aggregation Behavior of a Six-Membered Cyclic Frustrated Phosphane/Borane Lewis Pair: Formation of a Supramolecular Cyclooctameric Macrocyclic Ring System

Angew Chem Int Ed Engl. 2019 Jan 14;58(3):882-886. doi: 10.1002/anie.201811873. Epub 2018 Dec 12.

Abstract

A new six-membered cyclic frustrated phosphane/borane Lewis pair was liberated from its HB(C6 F5 )2 adduct by treatment with vinylcyclohexane. The system is an active frustrated Lewis pair that undergoes cycloaddition reactions with suitable π reagents and it splits dihydrogen. At room temperature in solution the new compound is a monomer, however, in the crystal and in solution at low temperature it aggregates to a thermodynamically favoured supramolecular macrocyclic cyclooctamer.

Keywords: boranes; frustrated Lewis pairs; macrocycles; phosphanes; self-assembly.