Towards a frustrated Lewis pair-ionic liquid system

An ionic liquid encompassing a bulky tertiary amine was synthesized and used as a dual solvent-reactant for the formation of a frustrated Lewis pair with tris(pentafluorophenyl) borane, forming a pseudo-frustrated Lewis pair-ionic liquid system. The ionic liquid-LA system is prone to self-ionization, i.e. with the formation of iminium and boron hydride species, which are able to form adducts with CO2. Compared to frustrated Lewis pairs operating in organic solvents of low polarity, more forcing conditions are required for the ionic liquid system. Calculations indicate that the anion of the ionic liquid interacts with the Lewis acidic boron center, hindering reactivity, and rationalizing the low reactivity observed. (C) 2017 Elsevier B.V. All rights reserved.