Dynamics of the reactions of O(1D) with HCl, DCl, and Cl2

Abstract

The reactions O('D)+HCI->OH+CI (1a) and OCI+H (1b), O('D)+DCl->OD+CI (2a) and OCI+D (2b), and 0(,D)+CI 2->OCI+CI (3) are studied at an average collision energy of 7.6, 7.7, and 8.8 kcal/mol for (1), (2), and (3), respectively. H, D, and CI atoms are detected by the resonance-enhanced multiphoton ionization technique. The average kinetic energies released to the products are estimated from Doppler profile measurements of the product atoms. The relative yields [OCI+H]/[OH+CI] and [OCI+D]/[OD+CI] are directly measured, and a strong isotope effect (HID) on the relative yields is found. The fine-structure branding ratios [Clep,d/[C1(2P 3/2)] of the reaction products are also measured. The results suggest that nonadiabatic couplings take place at the exit channels of the reactions (la) and (2a), while the reaction (3) is totally adiabatic.

A Crossed Molecular Beam Imaging Study of the O(1D2)+HCl→OH+Cl(2PJ=3/2, 1/2) Reaction

“…Both the spin-orbit excited ( 2 P J = 1/2 ) and ground ( 2 P J = 3/2 ) states of Cl were observed in the OH + Cl channel; [4,31] the yield of Cl*A C H T U N G T R E N N U N G ( 2 P 1/2 ) was found to be less than half of the degeneracy ratio between 2 P 1/2 and 2 P 3/2 , which indicates that an adiabatic reaction pathway leading to 2 P 3/2 is important. On the basis of the state-correlation diagram for 2 P W = 1/2, 3/2 (OH) and 2 P J = 3/2, 1/2 (Cl) in the linear geometry, Matsumi et al [4] suggested that the Cl*A C H T U N G T R E N N U N G ( Herein, we attempt to address some of these issues by the first measurement of the differential cross sections for the title reaction.…”

“…The high reactivity originates from an open-shell electronic configuration in the singlet state, which allows the O atom to insert into a chemical bond without a reaction barrier. The insertion results in a deep well on the ground-state potential energy surface (PES), which corresponds to stable species of H 2 O (X In addition to the ground-state pathway, recent experimental and theoretical studies [1][2][3] have revealed an abstraction process on the excited-state PESs with small reaction barriers [ % 2 kcal mol À1 for OA C H T U N G T R E N N U N G ( ) was measured by Matsumi et al [4] to be % 1:4 in a bulb experiment at the average collision energy of 7.6 kcal mol…”

“…In the minor ClO + H channel (1), a relatively large translational energy release (< f T > = 0.52) was observed. [4,5] Balucani et al [6] measured the angular distribution of the ClO product by a crossed molecular beam method. The observed angular distribution at the collision energy (E col ) of 12.2 kcal mol À1 was forward-backward symmetric with slight enhancement in the backward direction.…”

“…On the basis of the state-correlation diagram for 2 P W = 1/2, 3/2 (OH) and 2 P J = 3/2, 1/2 (Cl) in the linear geometry, Matsumi et al [4] suggested that the Cl*A C H T U N G T R E N N U N G ( Herein, we attempt to address some of these issues by the first measurement of the differential cross sections for the title reaction.…”

Quantum dynamical study of the O(D1)+HCl reaction employing three electronic state potential energy surfaces

“…The reaction of electronically excited oxygen with hydrochloric acid has been a focus of several experimental [1][2][3][4][5][6][7][8][9] and theoretical studies. The reaction plays an important role in the modeling of atmospheric chemistry and presents an interesting system for the study of fundamental dynamics.…”