TY - JOUR
T1 - Probing the dependence of long-range, four-atom interactions on intermolecular orientation
T2 - 3. hydrogen and iodine
AU - Darr, Joshua P.
AU - Loomis, Richard A.
AU - Ray-Helmus, Sara E.
AU - McCoy, Anne B.
PY - 2011/6/30
Y1 - 2011/6/30
N2 - Two-laser, action spectroscopy experiments have been performed in the I2B-X, ν′-0 spectral region on H 2•••I2 and D2••• I2 complexes to investigate the dependence of the H 2/D2 + I2 intermolecular interactions on orientation. The spectra contain features associated with at least two different conformers of the ground-state H2/D2••• I2(X,ν′′ = 0) complexes; one conformer has a preferred T-shaped geometry with the H2/D2 moiety localized in a potential minimum that is orthogonal to the I-I bond axis, and the second conformer has a linear geometry with the H2/D2 moiety positioned in minima at either end of the I2 molecule, along the bond axis. Those features associated with complexes containing para-H2(j = 0), ortho-H2(j = 1), ortho-D2(j = 0), and para-D 2(j = 1) are also assigned. The linear conformers are found to be more strongly bound than the T-shaped conformers with binding energies of 118.9(1.9) cm-1 versus 91.3-93.3 cm-1 for the ortho-H 2•••I2 complexes and 144.2(2.1) cm -1 versus 107.9 cm-1 for the para-D2• ••I2 complexes, respectively. Electronic structure calculations of the complexes containing ICl and I2 with H 2, He, Ne, and Ar were performed to reveal the nature of the interactions and to shed insight into the origins of the different binding energies. The most stable minima in the H2/D2 + I 2(B,ν′) excited-state potentials have T-shaped geometries. Calculated energies and probability amplitudes of the excited-state levels provide insight into the different excited-state intermolecular vibrational levels accessed by transitions of the two ground-state conformers.
AB - Two-laser, action spectroscopy experiments have been performed in the I2B-X, ν′-0 spectral region on H 2•••I2 and D2••• I2 complexes to investigate the dependence of the H 2/D2 + I2 intermolecular interactions on orientation. The spectra contain features associated with at least two different conformers of the ground-state H2/D2••• I2(X,ν′′ = 0) complexes; one conformer has a preferred T-shaped geometry with the H2/D2 moiety localized in a potential minimum that is orthogonal to the I-I bond axis, and the second conformer has a linear geometry with the H2/D2 moiety positioned in minima at either end of the I2 molecule, along the bond axis. Those features associated with complexes containing para-H2(j = 0), ortho-H2(j = 1), ortho-D2(j = 0), and para-D 2(j = 1) are also assigned. The linear conformers are found to be more strongly bound than the T-shaped conformers with binding energies of 118.9(1.9) cm-1 versus 91.3-93.3 cm-1 for the ortho-H 2•••I2 complexes and 144.2(2.1) cm -1 versus 107.9 cm-1 for the para-D2• ••I2 complexes, respectively. Electronic structure calculations of the complexes containing ICl and I2 with H 2, He, Ne, and Ar were performed to reveal the nature of the interactions and to shed insight into the origins of the different binding energies. The most stable minima in the H2/D2 + I 2(B,ν′) excited-state potentials have T-shaped geometries. Calculated energies and probability amplitudes of the excited-state levels provide insight into the different excited-state intermolecular vibrational levels accessed by transitions of the two ground-state conformers.
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U2 - 10.1021/jp201549d
DO - 10.1021/jp201549d
M3 - Article
C2 - 21568302
AN - SCOPUS:79959542773
VL - 115
SP - 7368
EP - 7377
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
SN - 1089-5639
IS - 25
ER -