Ja. Degouw et al., MEASURED AND CALCULATED MOBILITIES OF CLUSTER IONS DRIFTING IN HELIUMAND IN NITROGEN, International journal of mass spectrometry and ion processes, 167, 1997, pp. 281-289
Citations number
23
Categorie Soggetti
Spectroscopy,"Physics, Atomic, Molecular & Chemical
New experimental results are presented for the mobilities of (1) the H
3O+(H2O)(3) cluster ion drifting in He (the reduced zero-field mobilit
y K-0((0)) is 11.5 +/- 0.4 cm(2) V-1 s(-1), (2) NO+(CH3COCH3)(n) clust
er ions drifting in He (K-0((0)) = 7.5 +/- 0.4 cm(2) V-1 s(-1) for n =
2, K-0((0)) = 7.3 +/- 0.5 cm(2) V-1 s(-1) for n 3), and (3) the NO+(C
H3CN)(2) cluster ion drifting in N-2 (K-0((0))) = 1.70 +/- 0.06 cm(3)
V-1 s(-1)). These results together with other recently reported cluste
r ion mobilities in He are quantitatively explained using the hard-sph
ere collision model by von Helden et al. (J. Phys. Chem. 97 (1993) 818
2-8192). The role of ion-induced dipole interactions is investigated a
nd shown to be minor for the mobilities of all but the smallest ions i
n He. The existing data on cluster-ion mobilities in N-2. including th
e result here, are systematized. As a result of the stronger polarizab
ility of N-2, the hard-sphere collision model does not agree with the
data, and a better explanation is obtained using a simple model that i
ncludes ion-induced dipole interactions. The size of the cluster has o
nly a minor effect on the mobility in N-2. The remaining discrepancies
between the measured and calculated results are attributed to ion-qua
drupole or dipole induced-dipole interactions. (C) 1997 Elsevier Scien
ce B.V.