Crossed molecular beam study of the endoergic reaction Hg+I/sub 2/. -->. HgI+I from threshold to 2. 6 eV (c. m. )

Journal Article · Sat Oct 15 04:00:00 EDT 1977 · J. Chem. Phys.; (United States)

OSTI ID:7208476

Mayer, T M; Wilcomb, B E; Bernstein, R B

The endoergic reaction Hg+I/sub 2/..-->..HgI+I-1.15 eV has been studied by the crossed molecular beam technique over a range of average relative translational energy, E-bar/sub tr/, from 0.9 to 2.6 eV (c.m.). A supersonic seeded beam of Hg in H/sub 2/, of variable Hg velocity, is crossed by a thermal beam of I/sub 2/. In-plane angular distributions of the HgI product are measured as a function of E-bar/sub tr/, with an electron bombardment (EB) ionizer, mass filter detector. Center-of-mass (c.m.) product angular and recoil velocity distributions are deduced from the laboratory angular distributions by an iterative fitting procedure. The HgI angular distributions are bimodal, characteristic of a long-lived complex mechanism. The products' recoil energy distribution is peaked at abnormally high E'/sub tr/. The average value, E-bar'/sub tr/, increases monotonically with E-bar/sub tr/. Reaction proceeds essentially at the thermodynamic threshold (i.e., with no intrinsic activation barrier), and the post-threshold excitation function is found to be of the form sigma/sub R/(E/sub tr/) proportional (E-E/sub 0/)/sup s//E/sub tr/, where 1

• Research Organization: Chemistry Department, University of Texas at Austin, Texas 78712
• OSTI ID: 7208476
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 67:8; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640301* -- Atomic
Molecular & Chemical Physics-- Beams & their Reactions
640304 -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR DISTRIBUTION
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
BEAMS
CHEMICAL REACTIONS
COLLIDING BEAMS
COLLISIONS
DISTRIBUTION
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
HALOGENS
IODIDES
IODINE
IODINE COMPOUNDS
MERCURY
MERCURY COMPOUNDS
MERCURY HALIDES
MERCURY IODIDES
METALS
MOLECULAR BEAMS
MOLECULE COLLISIONS
NONMETALS