DFT studies of the electronic structure and geometry of 18-crown-6, hexaaza[18]annulene, and their complexes with cations of the heavier alkali and alkaline earth metals

Abstract

DFT calculations for M@C 12H 12N 6 and M@C 12H 24O 6 (where M = Rb +, Cs +, Sr 2+, and Ba 2+, C 12H 12N 6 = hexaaza[18]annulene, and C 12H 24O 6 = 18-crown-6) were performed using the recently developed model core potential parametrization. Results show that the ions bind more strongly to C 12H 12N 6 than to 18-crown-6 moiety; the difference is more pronounced for cations with smaller radii.