Accession Number : ADA309206
Title : Recognition by New Pyridino-18-crown-6 Ligands Containing Two Methyl, Two t-Butyl or Two Allyl Substituents on Chiral Positions Next to the Pyridine Ring for the Enantiomers of Chiral Organic Ammonium Perchlorates.
Descriptive Note : Technical rept.,
Corporate Author : BRIGHAM YOUNG UNIV PROVO UT DEPT OF CHEMISTRY
Personal Author(s) : Habata, Yoichi ; Bradshaw, Jerald S. ; Young, J. J. ; Castle, Steven L. ; Huszthy, Peter
PDF Url : ADA309206
Report Date : MAY 1996
Pagination or Media Count : 13
Abstract : The log K values for the interaction of new chiral pyridino-18-crown-6 ligands containing two substituents on chiral positions next to the pyridine ring with the enantiomers of a-phenylethylamonium perchlorate (PhEt) and a-(1-naphthyl)ethylammonium perchlorate (NapEt) were measured using a (1)H NMR titration method in a CDCl3/CD3OD (1/1) solvent mixture. The log K values indicate that these chiral pyridino-18-crown.-6 ligands have high complexing abilities and good enantiomeric recognition for the chiral organic ammonium perchiorates. The (1)H NMR titration experiments also show that the phenyl ring of the guest PhEt is almost parallel to the pyridine ring in the chiral diallyl- and dimethyl-substituted ligand complexes with chiral PhEt, and the phenyl ring is perpendicular to the pyridine ring in the chiral di-t-butyl-substituted ligand complex with PhEt. These results were supported by MM2 calculations.
Descriptors : *METHYL RADICALS, *LIGANDS, *ORGANIC COMPOUNDS, *BUTYL RADICALS, *PYRIDINES, *AMMONIUM PERCHLORATE, COMPLEX COMPOUNDS, MIXTURES, SOLVENTS, RINGS, PHENYL RADICALS, TITRATION.
Subject Categories : Organic Chemistry
Atomic and Molecular Physics and Spectroscopy
Distribution Statement : APPROVED FOR PUBLIC RELEASE