We performed cryogenic ion mobility-mass spectrometry to study dibenzo-crown-ether complexes with Na+ and K+ ions. Two bands were observed in distributions of collision cross section (CCS) of Na+ complexes. On the other hand, K+(dibenzo-30-crown-10) complex showed only one band. By comparing the experimental and theoretical CCSs of candidate structures, the two sets of conformers in Na+ complexes were assigned to open and closed forms in which benzene–benzene distances were long and short, respectively. For K+(dibenzo-30-crown-10), the one set of conformers was assigned to the closed forms.
Figure. Structures of K+(dibenzo-24-crown-8) complexes. These conformers are observed by cryogenic ion mobility-mass spectrometry.
