Michael W. Ellzy

Correlation of structure and vibrational spectra of the zwitterion L-alanine in the presence of water: an experimental and density functional analysis.

Infrared vibrational spectra were collected along with the vibrational circular dichroism (VCD) spectra for the zwitterions alpha-D-alanine, alpha-L-alanine, alpha-D-mannose and alpha-L-mannose as potassium bromide (KBr) pressed samples. VCD for D- and L-alanine dissolved in water was also measured and compared against the spectra resulting from KBr pressed samples. The experimental data were compared against the ab initio B3LYP/6-31G* optimized geometry. The zwitterion structure of alpha-L-alanine was stabilized by the addition of water molecules. Computationally, beta-L-mannose was studied and resulting expected VCD bands assigned. We present the molecular structures resulting VCD spectra and infrared vibrational spectra from experimentation as compared with the computed results.

Vibrational frequencies and structural determinations of 1,4-thioxane.

We present a detailed analysis of the structure and infrared spectra of 1,4-thioxane. The vibrational frequencies of the 1,4-thioxane molecule were analyzed using standard quantum chemical techniques. Frequencies were calculated at the MP2 and DFT levels of theory using the standard 6-31G* basis set. The structural transformation of the chemical agent bis (2-chloroethyl) sulfide (HD, mustard gas) and the related symmetry to a previously study compound(4) makes the symmetry of the 1,4-thioxane molecule an interesting candidate for study. The molecule exists normally in a Cs configuration similar to the chair form of cyclohexane. High-energy forms of 1,4-thioxane with C1 and C2 symmetry also exist.

Vibrational frequencies and structural determinations of di-vinyl sulfone

We present a detailed analysis of the structure and infrared spectra of di-vinyl sulfone. The vibrational frequencies of the di-vinyl sulfone molecule were analyzed using standard quantum chemical techniques. Frequencies were calculated at the MP2 and DFT levels of theory using the standard 6-311G* basis set. The structural transformation of the chemical agent bis(2-chloroehtyl) sulfide (HD, mustard gas) and the related symmetry to a previously study compounds [Spectrochim. Acta Part A 55 (1999) 121; Spectrochim. Acta Part A 57 (2001) 2417] makes the symmetry of the di-vinyl sulfone molecule an interesting candidate for study. The molecule exists normally in a C(2) configuration. High-energy forms of di-vinyl sulfone with C(S) and C(1) symmetries also exist.