Reactions of O(1D) with water and propane monomers and clusters were i
nvestigated via a crossed molecular beam experiment and by dissociatio
n of ozone in a water-ozone complex, applying laser-induced fluorescen
ce for the detection of the OH product. The rotational and spin-orbit
state populations were analyzed. A strong preference for the 2PI3/2 sp
in-orbit state of the OH product is observed. The new results presente
d here demonstrate the effect of the initial rotational temperature of
propane on the spin-orbit states distribution in the product OH. The
preference for the low 2PI3/2 state is attributed to conservation of e
lectronic angular momentum. It is conserved through the curve crossing
which occurs in the entrance channel and during the lifetime of the l
ong-lived collision complexes. A quantitative model is presented which
rationalizes all the experimental observations.