TY - JOUR
T1 - Probing the dependence of long-range, four-atom interactions on intermolecular orientation. 1. Molecular hydrogen and iodine monochloride
AU - Darr, Joshua P.
AU - Crowther, Andrew C.
AU - Loomis, Richard A.
AU - Ray, Sara E.
AU - McCoy, Anne B.
PY - 2007/12/27
Y1 - 2007/12/27
N2 - The dependence of the long-range interactions between molecular hydrogen and iodine monochloride on the geometry between the molecules is investigated. Laser-induced fluorescence and action spectroscopy experiments have identified multiple conformers of the o,/p-H2...I35,37Cl(X,v″:= 0) van der Waals complexes. A conformer with the hydrogen molecule localized at the iodine end of the dihalogen, most likely with C2v, symmetry, is significantly more stable than an asymmetric conformer with the hydrogen localized in the well oriented orthogonally to the I-Cl bond axis, D 0&Prime = 186.4(3) cm-1 versus 82.8(3) ≤ D 0″ ≤ 89.6(3) cm-1. Complexes containing the 0-H2(Z=1) species are more strongly bound than those with P-H 2(Z=0). The electronically excited o,p-H2⋯I 35Cl(A,v́) and O,p-H2⋯I35,37C1(B, v́) complexes are found to have preferred asymmetric structures with binding energies bracketed between 73.7-80.5 and 69.5-76.3 cm-1 for o-H2⋯ I35Cl(A,v́=23) and o-H 2⋯I35Cl(B,v́=3), respectively. Calculations of the H2-I35C1(B,v́=3) intermolecular vibrational energies and probability amplitudes undertaken using a scaled He + ICl(B,v́=3) potential enable us to make tentative assignments of the excited-state levels experimentally accessed.
AB - The dependence of the long-range interactions between molecular hydrogen and iodine monochloride on the geometry between the molecules is investigated. Laser-induced fluorescence and action spectroscopy experiments have identified multiple conformers of the o,/p-H2...I35,37Cl(X,v″:= 0) van der Waals complexes. A conformer with the hydrogen molecule localized at the iodine end of the dihalogen, most likely with C2v, symmetry, is significantly more stable than an asymmetric conformer with the hydrogen localized in the well oriented orthogonally to the I-Cl bond axis, D 0&Prime = 186.4(3) cm-1 versus 82.8(3) ≤ D 0″ ≤ 89.6(3) cm-1. Complexes containing the 0-H2(Z=1) species are more strongly bound than those with P-H 2(Z=0). The electronically excited o,p-H2⋯I 35Cl(A,v́) and O,p-H2⋯I35,37C1(B, v́) complexes are found to have preferred asymmetric structures with binding energies bracketed between 73.7-80.5 and 69.5-76.3 cm-1 for o-H2⋯ I35Cl(A,v́=23) and o-H 2⋯I35Cl(B,v́=3), respectively. Calculations of the H2-I35C1(B,v́=3) intermolecular vibrational energies and probability amplitudes undertaken using a scaled He + ICl(B,v́=3) potential enable us to make tentative assignments of the excited-state levels experimentally accessed.
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U2 - 10.1021/jp076465u
DO - 10.1021/jp076465u
M3 - Article
C2 - 18052140
AN - SCOPUS:38349143924
VL - 111
SP - 13387
EP - 13396
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
SN - 1089-5639
IS - 51
ER -