Well Plate Circular Dichroism Reader for the Rapid Determination of Enantiomeric Excess.
Circular dichroism (CD) spectropolarimeters typically employ one photoelastic modulator. However, spectropolarimeters employing two or even four modulators are more versatile and can be used to subvert common measurement errors arising from imperfectly isotropic samples or sample holders. Small linear anisotropies that can cause large errors inCDmeasurement can be associated with multi-well sample holders. Thus, high-throughputCDanalyses in multi-well plates have not yet been demonstrated. One such application is the determination of enantiomeric excess of a library of reaction products. Herein, a spectropolarimeter employing four photoelastic modulators and a translation stage was used to determine the enantiomeric excess of a family of chiral amine complexes much more rapidly than could be achieved with a robotic fluid injection system. These experiments are proof of concept for high-throughputCDanalysis. In practice, commercially available glass bottomed well plates are sufficiently strain free such that a simple instrument with just one photoelastic modulator and a vertical optical train should be able to deliver theCDwithout special considerations given herein. On the other hand, polystyrene well plates cannot be used in this way.
Department of Chemistry, The University of Texas at Austin, Austin, Texas, 78712, USA.
P
P
Metola
Department of Chemistry and Molecular Design Institute, New York University, New York, New York 10003, USA.
S M
SM
Nichols
Department of Chemistry and Molecular Design Institute, New York University, New York, New York 10003, USA.
B
B
Kahr
Department of Chemistry, The University of Texas at Austin, Austin, Texas, 78712, USA.
E V
EV
Anslyn