Dynamics of the reaction, Al+O-2-->AlO+O, was studied by using the crossed-beam technique at five collision energies from 6.9 to 25.3 kJ/mol. The Al atomic beam was generated by laser vaporization and crossed with the O-2 beam at a right angle. The product AlO was detected by laser-induced fluorescence of the AlO(B (2)Sigma(+)-X (2)Sigma(+)) transition and the rotational-vibrational distributions were determined. The observed rotational and vibrational distributions displayed greater populations in lower vibrational and rotational levels than expected statistically. Rotational distributions were also determined for two spin-orbit states of Al, Al(P-2(1/2)) and Al(P-2(3/2)), at two collision energies. At a collision energy of 12.2 kJ/mol, the higher energy spin-orbit excited state, Al(P-2(3/2)), showed lower reactivity, i.e., about one-third of the ground spin-orbit state, Al(P-2(1/2)). However, the rotational distributions for the two states were almost identical. Both the reactivity and rotational distributions for Al(P-2(1/2)) and Al(P-2(3/2)) became similar at a higher collision energy, 18.5 kJ/mol. These results suggest that the reaction of Al with O-2 proceeds via an intermediate complex. Both spin-orbit states lead to the complex, lose memory of the initial electronic state, and provide identical rotational distributions. (C) 2003 American Institute of Physics.