Detection of O(PJ3) atoms formed by reaction, Al+O2→ AlO+O under crossed-beam condition

Abstract

The vacuum ultraviolet laser-induced fluorescence technique was employed to detect the oxygen atoms formed by the reaction, Al+O(2)--> AlO+O. The measurements were carried out under the crossed-beam condition at 12.2 kJmol of collision energy. The relative populations of three spin-orbit states of O((3)P(J)) were determined to be 3.8, 1.0, and 0.2 for J=2, 1, and 0, respectively. They show nonstatistical populations, i.e., more population in O((3)P(2)) and less population in O((3)P(0)) than the statistical expectation. These populations were almost identical for two Al beam conditions where the relative concentrations of two spin-orbit states of Al, (2)P(1/2), and (2)P(3/2), are different. These results suggest that the reaction of Al with O(2) proceeds via an intermediate complex where the memory of the initial spin-orbit state is lost. Deviation from the statistical population of O((3)P(J)) implies the occurrence of the interaction among potential surfaces in the exit channel.

Correlation Study of the Spin–Orbit State-Resolved Scattering of Al(2P) in Oxidation Reaction and Nonreactive Collision

“…The excited O­( 3 P 1,0 ) channel is not considered in the Gaussian fit because our experiments using different carrier gases show that the two peaks with Ar as the carrier gas are the reaction peaks of the Al­( 2 P 1/2, 3/2 ) reactants, and no excited O­( 3 P 1,0 ) products were found in the TKER distribution of AlO­(high N ) + O products. A previous LIF experiment has also shown a dominant population of the ground O­( 3 P 2 ) at low E c , about 80% of O­( 3 P) . The Gaussian fit to the AlO­( N = 17/19) product yields a σ 3/2 /σ 1/2 value of about 0.5 ± 0.1, which is consistent with previous LIF experiments. , However, the Gaussian fit to the AlO­( N = 17/19) product shows that its tail extends into the region of the energy distribution of the high rotational AlO ( N = 31/33) product, and the area of this portion is included within the error bars for the AlO ( N = 31/33) products shown in Table .…”

“…, and also taking into account the intensity ratio of Al( 25 The Gaussian fit to the AlO(N = 17/19) product yields a σ 3/2 /σ 1/2 value of about 0.5 ± 0.1, which is consistent with previous LIF experiments. 21,23 However, the Gaussian fit to the AlO(N = 17/19) product shows that its tail extends into the region of the energy distribution of the high rotational AlO (N = 31/33) product, and the area of this portion is included within the error bars for the AlO (N = 31/33) products shown in Table 1.…”

“…The oxidation dynamics of the Al atom, an important process with applications in combustion and rocket propellants, has been studied experimentally and theoretically over the past 50 years. − The Al­( 2 P) atom has two spin–orbit split Al­( 2 P 1/2 ) and Al­( 2 P 3/2 ) states with the energy difference of 112 cm –1 . Chen et al .…”

Theoretical Study of Elementary Steps in the Reactions between Aluminum and Teflon Fragments under Combustive Environments

“…The oxidation reactions of aluminum atoms are of considerable interest in combustion because aluminum compounds are used as an ingredient in propellant and explosive formulations. Our goal is not to present a systematic study of the reaction of aluminum with oxygen, which has been extensively studied both theoretically ,,, and experimentally. ,− Rather, we focus on the chemistry of reaction 15 in Table and its potential role in the Al−Teflon combustion mechanism. Reaction 15, Al + O 2 → AlO + O, has some interesting features.…”

Integral and differential cross sections of reactions relevant to astrochemistry

“…Many of the reactions between neutral species involving radicals and open-shell atoms for which low temperature CRESU rate coefficients are available have also been investigated by crossed beam techniques. These include reactions of CN(X 2 S + ), [38][39][40][41] CH(X 2 P r ), 42 C 2 H(X 2 S + ), 43-44 C 2 (X 1 S + , a 3 P u ), [45][46][47][48] Al( 2 P J ), [49][50][51][52][53][54] B( 2 P J ), 25,[55][56][57] C( 3 P J ), [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76][77] Si( 3 P J ) 78 and S( 1 D 2 ) atoms. 35 A large number of the CMB studies have been carried out with the so-called universal machine developed by Lee et al 79 In this classic design, two collimated supersonic beams of reactants, with low divergence and low velocity spread, cross at right angles in a vacuum chamber.…”