title: IR low-temperature matrix and ab initio study on beta-alanine conformers.
abstract: For the first time the argon-matrix low-temperature FTIR spectra of beta-alanine are recorded. They reveal a quite complicated spectral pattern which suggests the presence of several beta-alanine conformers in the matrix. To interpret the spectra, the eighteen beta-alanine conformers, stable in the gas phase, are estimated at the B3LYP and MP2 levels combined with the aug-cc-pVDZ. Ten low-energy structures are reoptimized at the QCISD/aug-cc-pVDZ and B3LYP and MP2 levels by using the aug-cc-pVTZ basis sets. Assignment of the experimental spectra is undertaken on the basis of the calculated B3LYP/aug-cc-pVDZ anharmonic IR frequencies as well as careful estimation of the conformer population. The presence of at least three beta-alanine conformers is demonstrated. The detailed analysis of IR spectra points to the possible presence of five additional beta-alanine conformers.
authors.affiliation: National Medicines Institute, 30/34 Chełmska Street, 00-725 Warsaw, Poland. janek@il.waw.pl
authors.forename: Jan Cz
authors.initials: JC
authors.lastname: Dobrowolski
authors.forename: Michał H
authors.initials: MH
authors.lastname: Jamróz
authors.forename: Robert
authors.initials: R
authors.lastname: Kołos
authors.forename: Joanna E
authors.initials: JE
authors.lastname: Rode
authors.forename: Joanna
authors.initials: J
authors.lastname: Sadlej
mesh_terms: D019295:Computational Biology; D008958:Models, Molecular; D008968:Molecular Conformation; D013055:Spectrophotometry, Infrared; D013696:Temperature; D015091:beta-Alanine / Q000737:chemistry*
chemical_list: D015091:beta-Alanine