  Steric hindered frustrated Lewis pairs (FLPs) have been shown to activate
hydrogen molecules, and their reactivity is strongly determined by the
geometric parameters of the Lewis acid s and bases. A recent experimental study
showed that ionic liquids (ILs) could largely improve the effective
configuration of FLPs. However, the detailed mechanistic profile is still
unclear. Herein, we performed a molecular dynamics (MD) simulations, aimi ng to
reveal the effects of ILs on the structures of FLPs, and to present a rule for
selecting more efficient reaction media. For this purpose, mixture systems were
adopt consisting of the ILs [Cnmim][NTf2] (n= 6, 10, 14), and the typical FLP
(tBu)3P/B(C6F5)3 . Radial distribution function (RDF) results show that toluene
competes with (tBu)3P to interact with B(C6F5)3 , resulting in a relatively low
effective (tBu)3P/B(C6F5)3 complex. [Cnmim][NTf2] is more intended to form a
solvated shell surrounding the (tBu)3P/B(C6F5)3 , which increases the amount of
effective FLPs. Spatial distribution function (SDF) results show that toluene
formed a continuum solvation shell, which hinders the interactions of (tBu)3P
and B(C6F5)3 , while [Cnmim][NTf2] leave a relatively large empty space, which
is accessible by (tBu3)P molecules, resulting in a higher probability of Lewis
acids and bases interactions. Lastly, we find that the longer alkyl chain
length of[Cnmim] cations, the higher probability of effective FLPs.
