Title
Intramolecular interactions of L-phenylalanine: Valence ionization spectra and orbital momentum distributions of its fragment molecules.
Abstract
Intramolecular interactions between fragments of L-phenylalanine, i.e., phenyl and alaninyl, have been investigated using dual space analysis (DSA) quantum mechanically. Valence space photoelectron spectra (PES), orbital energy topology and correlation diagram, as well as orbital momentum distributions (MDs) of L-phenylalanine, benzene and L-alanine are studied using density functional theory methods. While fully resolved experimental PES of L-phenylalanine is not yet available, our simulated PES reproduces major features of the experimental measurement. For benzene, the simulated orbital MDs for 1e(1g) and 1a(2u) orbitals also agree well with those measured using electron momentum spectra. Our theoretical models are then applied to reveal intramolecular interactions of the species on an orbital base, using DSA. Valence orbitals of L-phenylalanine can be essentially deduced into contributions from its fragments such as phenyl and alaninyl as well as their interactions. The fragment orbitals inherit properties of their parent species in energy and shape (ie., MDs). Phenylalanine orbitals show strong bonding in the energy range of 14-20 eV, rather than outside of this region. This study presents a competent orbital based fragments-in-molecules picture in the valence space, which supports the fragment molecular orbital picture and building block principle in valence space. The optimized structures of the molecules are represented using the recently developed interactive 3D-PDF technique.
Year
DOI
Venue
2011
10.1002/jcc.21639
JOURNAL OF COMPUTATIONAL CHEMISTRY
Keywords
Field
DocType
L-phenylalanine,intramolecular interactions,valence ionization spectra,orbital momentum distributions,fragments-in-molecule
Molecular orbital,Orbital hybridisation,Slater-type orbital,Atomic physics,Molecular orbital theory,Computational chemistry,Chemistry,Non-bonding orbital,Valence bond theory,Modern valence bond theory,Molecular orbital diagram
Journal
Volume
Issue
ISSN
32
3
0192-8651
Citations 
PageRank 
References 
1
0.44
2
Authors
3
Name
Order
Citations
PageRank
Aravindhan Ganesan110.44
Feng Wang2387.16
Chantal T. Falzon311.12