Chemically-Responsive Complexation of A Diquaternary Salt with Bis(m‑phenylene)-32-Crown-10 Derivatives and Host Substituent Effect on Complexation Geometry

A chemically responsive diquaternary salt with π-extended surface was made. The host–guest complexation with chemo-responsiveness between three bis(m-phenylene)-32-crown-10 (BMP32C10) derivatives and this diquaternary salt guest was studied through the sequential addition of basic and acidic reagents (diethylamine and trifluoroacetic acid, respectively). Furthermore, the host-substituent effect on the complexation geometries of these three host–guest complexes, from taco to taco-type threaded to threaded structures by changing the substituent on BMP32C10 as shown by crystal structures, was also addressed.