Nanocrystalline Ag from supramolecular stabilization of metals in 4-tert-butylcalix[4]arene lattices.
Competition between intermolecular forces is a prime method for directing the formation of self-assembled structures without resorting to the use of covalently modified host molecules. In this study, we demonstrate how the competition between hydrogen bonding, coordinate bonding, and van der Waals interactions guides the formation of a complex crystalline clathrate based on a Ag-ethylenediamine coordination complex and 4-tert-butylcalix[4]arene. Owing to the coordinative flexibility of Ag and the stabilizing interactions with the calixarene framework, a four-coordinate Ag complex is included in the structure. Subsequent removal of the amine by heating the crystalline inclusion compound results in reduction of the Ag+ ion such that metallic Ag nanocrystals are formed, thus indicating that this self-assembly approach is a viable method for obtaining simple calixarene frameworks loaded with silver. In the light of the experimental evidence, we comment on how this process relates to the reduction of silver in other systems.
Brown
Philip O
PO
Materials, Structure, and Function Group, Steacie Institute for Molecular Sciences, National Research Council Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada.
Enright
Gary D
GD
Ripmeester
John A
JA