title: Determination of precise pyrimidine cationic structure by vacuum ultraviolet mass-analyzed threshold ionization spectroscopy.
abstract: The vibrational spectrum of a pyrimidine cation in the ground electronic state was obtained using vacuum ultraviolet mass-analyzed threshold ionization (VUV-MATI) spectroscopy. Accurate ionization energy of pyrimidine was determined from the 0-0 band position in the VUV-MATI spectrum and was measured by varying the PFI field to the zero field limit, which is 75,258 ± 7 cm(-1) (9.3308 eV). The spectrum displayed a large number of vibrational peaks, which could be nearly completely assigned through Franck-Condon analysis performed with variations of geometrical parameters at the B3LYP/cc-pVTZ level. Based on the excellent agreement between experimental and calculated results, the definite geometry of the pyrimidine cation in the ground electronic state was determined to be a planar structure with C2v symmetry with a decreased N-N distance in the ring.
authors: Department of Chemistry and Institute for Molecular Science and Fusion Technology, College of Natural Sciences, Kangwon National University, Chuncheon 200-701, Korea. chkwon@kangwon.ac.kr hlkim@kangwon.ac.kr.
authors: Jae Han
authors: JH
authors: Kim
authors: Ji Hye
authors: JH
authors: Lee
authors: Hyonseok
authors: H
authors: Hwang
authors: Hong Lae
authors: HL
authors: Kim
authors: Chan Ho
authors: CH
authors: Kwon
mesh_terms: D002412:Cations / Q000737:chemistry; D013058:Mass Spectrometry; D015394:Molecular Structure; D011743:Pyrimidines / Q000737:chemistry*; D011789:Quantum Theory; D013056:Spectrophotometry, Ultraviolet; D014618:Vacuum
chemical_list: D002412:Cations; D011743:Pyrimidines; C030986:pyrimidine