Probing Through-Space Polar−π Interactions in 2,6-Diarylphenols

Although
it is well established that the acidity of phenol can
be fine-tuned with substituents on its aromatic ring via through-bond
effects, the role of through-space effects on the acidity of phenols
is presently poorly understood. Here, we present integrated experimental
and computational studies on substituted 2,6-diarylphenols that demonstrate
the essential contribution from through-space OH−π interactions
and O––π interactions in the observed
trends in proton affinities and acidities of 2,6-diarylphenols.