Thermodynamic and NMR Studies of Solvent Effect on Enantiomeric Recognition for a Chiral Organiz Ammonium Cation by Chiral Diketopyridino-18- Crown-6 Type Ligands at 25.0 deg C.

Abstract

Three chiral diketopyridino-18-crown-6 type macrocycles have been shown to exhibit a high degree of enantiomeric recognition toward alpha-(1- naphthyl)ethylammonium perchlorate (NapEt) in various ratios of chloroform/ methanol (CDCl3/CD3OD) and 1,2-dichloroethane/methanol (C2H4Cl2/CH3OH) solvent mixtures (from 100% to 10% methanol component). In most cases differences in log K values (delta(log) K) for (R)- and (S)-NapEt complexation with the chiral macrocycles are larger than 0.5. The degree of the enantiomeric recognition indicated by the delta(log) K value changes noticeably with the binary solvent components. The recognition is better in the solvents having a moderate methanol component than in the binary solvents having either a high a low methanol component. The highest degree of recognition is observed in 6/4 (v/v) CDCl3/ CD3OD and C2H4Cl2/CH3OH solvent mixtures and in a 7/3 (v/v) C2H4Cl2/CH3OH mixture for chiral (S,S)-1 macrocycle. (Author)

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Document Details

Document Type
Technical Report
Publication Date
May 11, 1994
Accession Number
ADA279893

Entities

People

  • Cheng Y. Zhu
  • Jerald S. Bradshaw
  • Reed Izatt
  • Xian X. Zhang

Organizations

  • Brigham Young University

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Communities of Interest

  • C4I

DTIC Thesaurus Topics

  • Alcohols
  • Calorimeters
  • Chemical Synthesis
  • Chemistry
  • Enantiomers
  • Enthalpy Changes
  • Heat Loss
  • Methanols
  • Military Research
  • Molecules
  • Peak Values
  • Polarity
  • Recognition
  • Titration
  • United States
  • United States Government
  • Volume

Fields of Study

  • Chemistry

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  • Organic Chemistry