Crown ether and cryptand intercalation processes into 2:1 phyllosilicates are exothermic. The nature of ligand and the nature of the interlayer cations are the most important factors influencing the net heat of intercalation. The enthalpy of intercalation is more exothermic than that of the corresponding complexation reaction of the same macrocycle with the same cation in homogeneous medium. The characteristics of the host silicate as well as the solvent used in the intercalation process also influence the enthalpy. The thermal treatment of the intercalated materials shows that the complexes remain unaltered up to 300°C under nitrogen.