Atomic Alignment Effect in the Dissociative Energy Transfer Reaction of Metal Carbonyls (Fe(CO)5, Ni(CO)4) with Oriented Ar (3P2, MJ=2)

The atomic alignment effect has been studied for the dissociative energy transfer reaction of metal carbonyls (Fe(CO)(s), Ni(CO)(4)) with the oriented Ar (P-3(2), M-J = 2). The emission intensity from the excited metal products (Fe*,Ni*) has been measured as a function of the atomic alignment in the collision frame. The selectivity of the atomic orbital alignment of Ar (P-3(2), M-J = 2) (rank 2 moment, a(2)) is found to be opposite for the two reaction systems; the Fe(CO)(s) reaction is favorable at the H configuration (positive a(2)), while the Ni(CO)(4) reaction is favotable at the I configuration (negative a2). Moreover, a significant spin alignment effect (rank :4 moment, a(4)) is recognized only in the Ni(CO)(4) reaction. The atomic alignment effect turns out to be essentially different between the two reaction systems; the Fe(CO)(s) reaction is controlled by the configuration of the half-filled 3p atomic orbital of Ar (P-3(2)) in the collision frame (L dependence), whereas the Ni(CO)(4) reaction is controlled by the configuration of the total angular moment J (including spin) of,Ar (P-3(2)) in the collision frame (J dependence). As the origin of J dependence observed only in the Ni(CO)(4) reaction, the correlation (and/or the interference) between two electron exchange processes via the election rearrangements is proposed.