Pseudopolymorphism of Aliphatic Amine/4-tert-Butylcalix[4]arene Inclusion Compounds: Supramolecular Stabilization as a Route to Polar Clusters and Layers

摘要

4-tert-Butylcalix[4]arene (4tBC4A) is a versatile host capable of forming a variety of 1:1 and 2:1 inclusion compounds typically stabilized through van der Waals interactions.Preliminary studies in our group have demonstrated that inclusion of n-butyl-amine in 4tBC4A results in a series of pseudopolymorphic inclusion compounds,including a new 3:1 inclusion motif.Using a combination of SCXRD,TGA,solid state NMR,and PXRD,we now elaborate upon the relationship between these pseudopolymorphs.We also demonstrate that larger amines demonstrate a similar degree of pseu-dopolymorphism,allowing for the production of customized materials using self-assembly guided by competing weak forces.Finally,we comment on the structural implications of the relative dominance such forces in the formation of calixarene-based supramolecular frameworks.