Accession Number : ADA296283
Title : Fourier Transform Ion Cyclotron Resonance Mass Spectrometry as a Probe of Chiral Recognition.
Descriptive Note : Technical rept.,
Corporate Author : BRIGHAM YOUNG UNIV PROVO UT DEPT OF CHEMISTRY
Personal Author(s) : Dearden, David V. ; Dejsupa, Chandin ; Liang, Yongjiang
PDF Url : ADA296283
Report Date : 22 JUN 1995
Pagination or Media Count : 17
Abstract : We have employed Fourier transform ion cyclotron resonance (FTICR) mass spectrometry to investigate the recognition of chiral amines by chiral crown ether hosts. Our prior studies involved competition between a chiral ligand and an achiral ligand for the enantiomers of a chiral ammonium ion. Conditions were chosen so equilibrium was attained in the exchange of each enantiomeric host between the two guests. Comparison of the equilibrium constants for the two enantiomers yields a measurement of the relative degree of recognition of the chiral host for the two guests. These studies were hampered by the relatively low volatility of the ligands, which led to difficulties in introducing them into the vacuum chamber and in measuring the partial pressures. To circumvent these problems, we have developed a new procedure wherein the relatively involatile chiral ligand is easily ionized using electrospray ionization to produce a protonated host molecule. The protonated host is captured in the FTICR trapping cell. Neutral amines, which are generally fairly volatile, are also readily introduced into the cell, where they react with the protonated host to form crown-ammonium complexes. Measurement of the partial pressures of the two amines is straightforward. jg p.4
Descriptors : *FOURIER TRANSFORMATION, *IONS, *AMINES, *CYCLOTRON RESONANCE, *MASS SPECTROMETRY, PROBES, COMPLEX COMPOUNDS, NEUTRAL, EQUILIBRIUM(GENERAL), PROTONS, VACUUM CHAMBERS, CONSTANTS, LIGANDS, IONIZATION, ETHERS, VOLATILITY, AMMONIUM COMPOUNDS, PARTIAL PRESSURE.
Subject Categories : Physical Chemistry
Nuclear Physics & Elementary Particle Physics
Distribution Statement : APPROVED FOR PUBLIC RELEASE