Autor: |
Guo, Changning, Shah, Rekha D., Dukor, Rina K., Cao, Xiaolin, Freedman, Teresa B., Nafie, Laurence A. |
Zdroj: |
Applied Spectroscopy; September 2005, Vol. 59 Issue: 9 p1114-1124, 11p |
Abstrakt: |
The first use of near-infrared (NIR) Fourier transform vibrational circular dichroism (FT-VCD) to follow changes in the enantiomeric excess (EE) of chiral sample molecules in time using a flow-cell sampling apparatus is reported. Simultaneous changes in the fractional composition and the EE of a mixture of two different chiral molecules were monitored as a function of time. This simulates the progress of the chemical reaction from a chiral reactant to a chiral product where the mole fractions and EE values of both species may change with time. For the molecules studied, α-pinene, camphor, and borneol, the accuracy of following EE changes for one species alone is approximately 2%, while for simultaneously following EE changes in two species it is approximately 3% for 30 min sampling periods at 16 cm−1spectral resolution. These findings demonstrate the potential for VCD to be used in the NIR region for real-time monitoring of the composition and %EE of chemical reactions involving the synthesis of chiral molecules. |
Databáze: |
Supplemental Index |
Externí odkaz: |
|