“Clickable” pillar[5]arenes

Introduction of bulky substituents such as benzyl and pyrenyl groups using click reactions inhibited or slowed the rotation of the units on the NMR chemical shift timescale. The perpyrenylated pillar[5]arene showed a thermally-responsive excimer emission, but a unit model of the perpyrenylated pillar[5]arene did not exhibit such a response.