Pseudopolymorphism of aliphatic amine/4-tert-butylcalix[4]arene inclusion compounds: supramolecular stabilization as a route to polar clusters and layers.
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-butylamine 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 pseudopolymorphism, 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.
Brown
Philip O
PO
Materials, Structure and Function Group, Steacie Institute for Molecular Sciences, National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario, K1A 0R6 Canada.
Udachin
Konstantin A
KA
Enright
Gary D
GD
Ripmeester
John A
JA