A. Mouhandes et Aj. Stace, INFRARED PHOTOFRAGMENTATION SPECTRA OF C2H4-CENTER-DOT(NO)(N)(+) CLUSTER IONS, International journal of mass spectrometry and ion processes, 159, 1996, pp. 185-196
Citations number
26
Categorie Soggetti
Spectroscopy,"Physics, Atomic, Molecular & Chemical
A line-tuneable CO2 laser has been used to excite one or more vibratio
nal modes in ethylene molecules resident on sizeselected C2H4(NO)(n)() cluster ions, for n in the range 2-20. Excitation is followed by the
observation of three separate fragmentation channels: -C2H4, -NO and
-2NO, whose relative intensities are found to be extremely sensitive t
o cluster size. The most marked transitions in fragmentation pattern a
re found to occur between odd- and even-sized cluster ions, with decay
channels favouring the formation of even electron ions. A summation o
f fragment ion intensities as a function of laser wavelength is used t
o determine infrared absorption profiles. Those profiles associated wi
th several of the even-sized ions show evidence of two prominent absor
ption features, one of which is attributed to the nu(7) infrared activ
e vibrational mode in ethylene. A second absorption feature is tentati
vely assigned as the nu(8) mode which, under normal circumstances, is
Raman active; however, a mechanism is proposed whereby the ethylene mo
lecule could become distorted.