Enantiomeric recognition by chiral pyridino-18-crown-6 for 1-naphthylethylamine. The effect of alkyl substituents on the macrocycle ring

Jon K. Hathaway, Reed M. Izatt, Jerald S. Bradshaw, Cheng Y. Zhu, P. Huszthy

Research output: Contribution to journalArticle

9 Citations (Scopus)


Molecular recognition of three chiral pyridino-18-crown-6 macrocycles with various dialkyl substituents for (R)- and (S)-[α-(1-naphthyl)ethyl]ammonium perchlorate (NapEt) has been determined by isoperibol titration calorimetry and compared to values already determined for the chiral di-methyl- and di-tert-butyl-sub-stituted crowns. Possible mechanisms of recognition for these systems are discussed using the thermodynamic values log K, ΔH, and TΔS. Macrocycles with the bulky substituents tert-butyl, isobutyl, and sec-butyl showed better recognition than those with the less bulky isopropyl and methyl substituents. In the case of macrocycles with bulky substituents, recognition of the enantiomers of NapEt was mainly the result of differences in entropy value changes. With macrocycles having less bulky substituents, reognition was mainly the result of differences in enthalpy value changes.

Original languageEnglish
Pages (from-to)9-13
Number of pages5
JournalSupramolecular Chemistry
Issue number1
Publication statusPublished - May 1 1995


ASJC Scopus subject areas

  • Chemistry(all)

Cite this