TY - JOUR
T1 - Role of projectile and surface temperatures in the energy transfer dynamics of protonated peptide ion collisions with the diamond {111} surface
AU - Rahaman, Asif
AU - Collins, Othalene
AU - Scott, Chavell
AU - Wang, Jiangping
AU - Hase, William L.
PY - 2006/7/13
Y1 - 2006/7/13
N2 - The effects of temperature on energy transfer during collisions of protonated diglycine ions, Gly 2-H +, with a diamond {111} surface were investigated by chemical dynamics simulations. The simulations were performed for a collision energy of 70 eV and angle of 0° with respect to the surface normal. In one set of simulations the initial surface temperature, T surf, was varied from 300 to 2000 K, while the Gly 2-H + vibrational and rotational temperatures were maintained at 300 K. For the second set of simulations the Gly 2-H + vibrational temperature, T vib. was varied from 300 to 2000 K, keeping both the Gly 2-H + rotational and surface temperatures at 300 K. Increasing either, the surface temperature or Glya 2-H + vibrational temperature to values as high as 2000 K has, at most, only a negligible effect on the partitioning of the incident collision energy to the surface and to the vibrational and rotational modes of Gly 2-H +. To a good approximation, the initial surface and peptide ion energies are nearly adiabatic during the collisional energy transfer. This adiabaticity of the initial peptide ion energy agrees with experiments (J. Phys. Chem. A 2004, 108, 1). A more quantitative analysis of the effects of T vib and T surf shows there are small, but noticeable, effects on the energy transfer efficiencies. Namely, increasing the vibrational or surface temperature results in a near-linear decrease in the energy transfer to the degrees of freedom associated with this temperature.
AB - The effects of temperature on energy transfer during collisions of protonated diglycine ions, Gly 2-H +, with a diamond {111} surface were investigated by chemical dynamics simulations. The simulations were performed for a collision energy of 70 eV and angle of 0° with respect to the surface normal. In one set of simulations the initial surface temperature, T surf, was varied from 300 to 2000 K, while the Gly 2-H + vibrational and rotational temperatures were maintained at 300 K. For the second set of simulations the Gly 2-H + vibrational temperature, T vib. was varied from 300 to 2000 K, keeping both the Gly 2-H + rotational and surface temperatures at 300 K. Increasing either, the surface temperature or Glya 2-H + vibrational temperature to values as high as 2000 K has, at most, only a negligible effect on the partitioning of the incident collision energy to the surface and to the vibrational and rotational modes of Gly 2-H +. To a good approximation, the initial surface and peptide ion energies are nearly adiabatic during the collisional energy transfer. This adiabaticity of the initial peptide ion energy agrees with experiments (J. Phys. Chem. A 2004, 108, 1). A more quantitative analysis of the effects of T vib and T surf shows there are small, but noticeable, effects on the energy transfer efficiencies. Namely, increasing the vibrational or surface temperature results in a near-linear decrease in the energy transfer to the degrees of freedom associated with this temperature.
UR - http://www.scopus.com/inward/record.url?scp=33746353701&partnerID=8YFLogxK
U2 - 10.1021/jp057159o
DO - 10.1021/jp057159o
M3 - Article
C2 - 16821824
AN - SCOPUS:33746353701
SN - 1089-5639
VL - 110
SP - 8418
EP - 8422
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 27
ER -