Conformational effects on circular dichroism in the photoelectron angular distribution.

Area of Science:

• Quantum chemistry
• Computational physics
• Molecular spectroscopy

Background:

• Conformational analysis is crucial for understanding molecular properties.
• Dynamical properties of molecules are often sensitive to their 3D structure.
• Previous methods for conformational analysis can be computationally intensive.

Purpose of the Study:

• To investigate the sensitivity of cross section, asymmetry, and dichroic parameters to molecular conformation.
• To explore the utility of the dichroic parameter as a tool for conformational analysis.
• To apply the B-spline density-functional method to study molecular dynamics.

Main Methods:

• Application of the B-spline density-functional method.
• Systematic study of core and valence orbital parameters.
• Analysis of conformational changes in (1R, 2R)-1,2-dibromo-1,2-dichloro-1,2-difluoroethane.
• Investigation of methyl rotation in methyloxirane.

Main Results:

• The dichroic parameter shows high sensitivity to molecular conformation, unlike cross section and asymmetry parameters.
• Dramatic sensitivity of the dichroic parameter profile to methyl rotation in methyloxirane was observed.
• Boltzmann averaging accurately reproduced experimental profiles for minimum-energy conformations.

Conclusions:

• The dichroic parameter is a valuable dynamical property for molecular conformational analysis.
• The B-spline density-functional method provides accurate insights into molecular dynamics and conformation.
• Computational methods can effectively predict and analyze molecular conformational behavior.