Influence of hydrogen bonding on the conformational stability of calix[4]crown-4 ether

Abstract

The conformational characteristics of calix[4]crown-4 ether have been studied using different quantum mechanical methods. The structures optimized by the HF/6-31G(d), B3LYP/6-31G(d)/ 6-311G(d), MPW1B95/6-31G(d), MPW1PW91/6-31G(d) and M062X methods. The relative stability of different conformers follow the order: cone > partial-cone > 1,3-alternate. Short O-H^…π and intramolecular hydrogen bonds are observed in different conformers of calix[4]crown-4 ether. The relative stability of different conformers is dependent on the number and strength of intramolecular non-covalent interactions.