Vibrational structures of predissociating methylamines „ CH 3 NH 2 and CH 3 ND 2 ... in à states : Free internal rotation of CH 3 with respect to NH 2

Content Provider	Semantic Scholar
Author	Baek, Sun Jong Choi, Kyo-Won Choi, Young Shin Kima, Sang Kyu
Copyright Year	2002
Abstract	Resonantly-enhanced one-color two-photon ~111! ionization spectra of jet-cooled methylamines (CH3NH2 and CH3ND2) reveal the vibrational structures of these molecules in predissociative à states. Rotational fine structure is clearly resolved for CH 3ND2 at the origin and first wagging vibrational level in the excited state. The spectral linewidth becomes homogeneously broadened to give only vibrationally resolved spectral features for the higher vibrational energy levels of CH3ND2 (Ã). From the spectral analysis of the ÖX transition of CH3ND2, it is found that the methyl moiety rotates nearly freely about the C–N axis with respect to the amino group in the à state, indicating that the removal of an electron from the nonbonding orbital of N is responsible for the free internal rotation. Vibrational levels are only barely resolved in the ÖX excitation spectrum of CH3NH2 due to severe homogeneous line-broadening, indicating ultrashort lifetimes of ;0.4 ps for predissociating CH3NH2 molecules in theà state. Spectral interpretation of the ÖX excitation spectrum of CH3NH2 is carried out by the comparison with that of CH 3ND2, giving the confirmative vibrational assignment of methylamines in à states for the first time. The dramatic difference of CH3NH2 and CH3ND2 in their lifetimes inà states suggests that the major dissociation channel of the excited methylamine may be the N–H ~or D! bond dissociation. ©2002 American Institute of Physics. @DOI: 10.1063/1.1518005 #
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://koasas.kaist.ac.kr/bitstream/10203/10815/1/7.pdf
Language	English
Access Restriction	Open
Subject Keyword	Apache Axis CDISC SDTM Not Done Terminology Electron Energy level Excitation Excited state Genus Axis Methylamines Molecular orbital Neonatal hemochromatosis NetHack Norsk Data Photons Spectral density estimation methylamine newton
Content Type	Text
Resource Type	Article