Solid‐State Structure and Formation of Organized Molecular Films of Azacalixarene Derivatives Containing Dioctyl Groups and Their Metal‐Capturing Properties

ABSTRACT

The solid‐state structure of an azacalixarene derivative (aCX‐2C ₈ ) containing two octyl chains and a cyclic moiety was investigated and a monolayer was prepared on the water surface to evaluate its metal adsorption behavior. The powder x‐ray diffraction (XRD) profile of aCX‐2C8 revealed that a triclinic packing model could be applied using reciprocal lattice analysis. The monolayer of aCX‐2C ₈ on the water surface exhibited a condensed tendency but its limiting area was broad, at 70 Å ² . The monolayer surface exhibited a hollow, doughnut‐like morphology at the nanometer scale. When the multilayers were annealed, the out‐of‐plane XRD profile revealed a highly layered structure with an upright conformation. The hydrophilic properties of aCX‐2C ₈ were weak, and it was inferred that, upon two‐dimensional compression, the system formed a conformation that minimized contact with the water surface. Furthermore, the azacalixarene ring moiety was capable of capturing monovalent, divalent, and trivalent metal cations present in the subphase.