JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY, cilt.50, ss.165-171, 2004 (SCI-Expanded)
The X-ray crystal structure of IX, perchlorate salt of R-(-)-2-ethyl-N-benzyl-4,7,19,13-tetraoxa-8,9-benzo-1-azacyclopentadec-8-ene has been determined. In the molecule, the protonated nitrogen atom participates in two N-(HO)-O-... hydrogen bonds. The unusually high proton affinity of aza crown ether leads to the formation of diastreomer instead of complex formation with chiral R-(+)-1-phenyl ethyl ammonium perchlorate and S-(-)-1-phenyl ethyl ammonium perchlorate. The complex ability of host ethers was evaluated in terms of structural modification.