Fundamental Investigations and Analysis of Chiral Matter Using Simple Spectroscopic Techniques

Fundamental investigations of circular dichroism were performed on (R)-(+)-3- methylcyclopentanone, (R)-(-)-2-butylamine, and (S)-(+)-2-butylamine in the liquid and vapor phase to show that solvents often have a structure-masking effect on the circular dichroism for a given molecule. Also, the solid state circular dichroism of cubic sodium chlorate crystals was successfully measured in the midst of adverse experimental circumstances. With these single photon circular dichroism studies at hand, a new technique for measuring circular dichroism was introduced for an advanced investigation of (R)-(+)-3-methylcyclopentanone. The resonance enhanced multiphoton ionization of (R)-(+)-3-methylcyclopentanone was performed with left and right circularly polarized laser light at a wavelength of 397.5 nm. This technique gave a dissymmetric factor g of 4.1 ± 0.23 x 10-2 in favor of the left circularly polarized light.

Parity violating energy difference studies were conducted on the enantiomers of alanine and valine. The conversion of one enantiomer to the other at 273 K was found not to occur due to temperature dependent studies of circular dichroism, x-ray diffraction, C-13 solid state NMR, Raman spectroscopy, magnetic susceptibility, differential scanning calorimetry, and theoretical calculations.

Highly intense 1064 nm pulsed laser light was used to induce crystallization in sodium chlorate, sodium bromate, and glycine aqueous solutions. The symmetry of sodium chlorate crystals and the asymmetry of sodium bromate crystals were broken by right circularly polarized and linearly polarized light, respectively. The g-polymorph of glycine was produced by an acidic pH change induced by the intense laser light. Under a Sr-90 source, 1,1’-binaphthyl crystallized into crystals showing a slight enantiomeric excess.