title: Identification of Serine Conformers by Matrix-Isolation IR Spectroscopy Aided by Near-Infrared Laser-Induced Conformational Change, 2D Correlation Analysis, and Quantum Mechanical Anharmonic Computations.
abstract: The conformers of α-serine were investigated by matrix-isolation IR spectroscopy combined with NIR laser irradiation. This method, aided by 2D correlation analysis, enabled unambiguously grouping the spectral lines to individual conformers. On the basis of comparison of at least nine experimentally observed vibrational transitions of each conformer with empirically scaled (SQM) and anharmonic (GVPT2) computed IR spectra, six conformers were identified. In addition, the presence of at least one more conformer in Ar matrix was proved, and a short-lived conformer with a half-life of (3.7 ± 0.5) × 10(3) s in N2 matrix was generated by NIR irradiation. The analysis of the NIR laser-induced conversions revealed that the excitation of the stretching overtone of both the side chain and the carboxylic OH groups can effectively promote conformational changes, but remarkably different paths were observed for the two kinds of excitations.
authors.affiliation: †Laboratory of Molecular Spectroscopy, Institute of Chemistry, Eötvös University, PO Box 32, H-1518, Budapest 112, Hungary.
authors.forename: Eszter E
authors.initials: EE
authors.lastname: Najbauer
authors.affiliation: †Laboratory of Molecular Spectroscopy, Institute of Chemistry, Eötvös University, PO Box 32, H-1518, Budapest 112, Hungary.
authors.forename: Gábor
authors.initials: G
authors.lastname: Bazsó
authors.affiliation: ‡Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Apóstolo
authors.affiliation: ‡Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Fausto
authors.affiliation: §Physics Department and International Centre for Quantum and Molecular Structure, Shanghai University, Shanghai, 200444 China.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Biczysko
authors.affiliation: ∥Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Barone
authors.affiliation: †Laboratory of Molecular Spectroscopy, Institute of Chemistry, Eötvös University, PO Box 32, H-1518, Budapest 112, Hungary.
authors.forename: György
authors.initials: G
authors.lastname: Tarczay
mesh_terms: D007834:Lasers; D008958:Models, Molecular; D008968:Molecular Conformation; D011789:Quantum Theory; D012694:Serine / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013816:Thermodynamics
chemical_list: D012694:Serine