Complexation Thermodynamics of Crown Ethers. Part 5. 1,2 Substitution and Lariat Effects upon Cation Complexation with Aza-Crown Ethers

The effects of sidearm(s) introduced to aza-crown ethers upon their complexation thermodynamics and relative cation selectivities for alkali metal ions have been investigated by titration calorimetry; using the present and reported data, the complexation behaviour of several C- and N-pivot lariats with (3m + n)-crown-m (m = 5,6; n = 0, 1) skeletons is discussed comparatively and globally from the thermodynamic point of view.