Large. delta. v' transitions and isotope effects in the crossed beams inelastic scattering of I/sub 2/*(v' = 35) from H/sub 2/ and D/sub 2/

Journal Article · Thu Mar 24 04:00:00 EST 1988 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100317a003· OSTI ID:5218044

Krajnovich, D J; Butz, K W; Du, H; Parmenter, C S

Rotationally and vibrationally inelastic scattering form the level v' = 35 with J' = 8-11 in the B O/sub u//sup +/ electronic state of I/sub 2/ have been followed in a crossed molecular beams experiment using H/sub 2/ and D/sub 2/ target gases. Center-of-mass collision energies are 89 and 103 meV, respectively. I/sub 2/ B O/sub u//sup +/ is excited by a laser pump and the inelastic scattering is followed by dispersed B ..-->.. X fluorescence. The signal-to-noise is good enough to obtain relative cross sections for I/sub 2/ scattering for ..delta..v's extending to +- 7. The cross sections are remarkably symmetric with respect to gain vs loss of vibrational quanta. They decrease exponentially with increasing absolute value ..delta..v' divides for each target, but H/sub 2/ has a steeper decline. Collision momentum rather than velocity differences appears to be responsible for this isotope effect. The mean vibrational energy change per state-changing collision is only about -9 cm/sup -1/ for both H/sub 2/ and D/sub 2/, a small fraction of the 60-cm/sup -1/ vibrational quantum size. Rotationally inelastic scattering produces 2-3 times more rotational excitation with the heavier isotope D/sub 2/, a consequence of angular momentum conservation

• Research Organization: Indiana Univ., Bloomington (USA)
• OSTI ID: 5218044
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 92:6; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ANGULAR MOMENTUM
COLLISIONS
DATA
DEUTERIUM
ELEMENTS
EMISSION SPECTROSCOPY
ENERGY LEVELS
ENERGY RANGE
EV RANGE
EXCITED STATES
EXPERIMENTAL DATA
FLUIDS
FLUORESCENCE SPECTROSCOPY
GASES
HALOGENS
HYDROGEN
HYDROGEN ISOTOPES
INELASTIC SCATTERING
INFORMATION
IODINE
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
MILLI EV RANGE
MOLECULE COLLISIONS
NONMETALS
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
ROTATIONAL STATES
SCATTERING
SPECTROSCOPY
STABLE ISOTOPES
VIBRATIONAL STATES