Interlayer Adsorption of Macrocyclic Compounds (Crown-Ethers and Cryptands) in 2:1 Phyllosilicates: II. Structural Features

Abstract

AbstractIntercalation of macrocyclic compounds (crown-ethers and cryptands) in 2:1 charged phyllosilicates is a topotactic reaction, the lamellar structure of the pristine material being preserved. X-ray diffraction and spectroscopic (IR, NMR) results provide information on the main structural characteristics of the intercalates. Guest species, which form 1 : 1 or 2 : 1 ligand/cation intracrystalline complexes, lie flat or tilting between the host layers as can be deduced from the increase in the basal space of the silicate and the dichroic effect observed on the CH and NH IR vibration bands of the guest species, after intercalation. The chemical shift observed in 23Na NMR spectra of the solids is associated with the different environment of the cation before and after the intercalation process.