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.
Ellzy
Michael W
MW
US Army Edgewood Research Development and Engineering Center, Aberdeen Proving Grounds, Aberdeen, MD 21010-5423, USA. mwellzy@sbccom.apgea.army.mil
Jensen
James O
JO
Hameka
Hendrik F
HF
Kay
Jack G
JG
D000409:Alanine / Q000737:chemistry*; D002942:Circular Dichroism; D013055:Spectrophotometry, Infrared; D014867:Water / Q000737:chemistry*
D014867:Water; D000409:Alanine