Summary: Volume206,number 5,6 CHEMICALPHYSICSLETTERS 1 May 1993
Femtochemistry of the liquid phase laser-induced harpoon reaction
between Cl2 and Xe. Observation of bond formation in real time
R. Zadoyan and V.A. Apkarian
DepartmentofChemistry, Universityof California.Irvine,CA9271%USA
Received 11 February 1993;in tinal form 18March 1993
The liquidphase, two-photon induced intermolecular chargetransfer transition, Cl2t Xet 2hu+Xe+ClF, in which the photon
is resonant with the dissociative Cl1(`ll,J intermediate state, is shownto proceed on a time scaleshorter than 100fs.The process
is therefore classified as a coherent, cooperative absorption. The subsequent evolution of the harpoon reaction, Xe+Clr +
Xe+Cl- +CI, which in liquid Xe further proceeds to form Xe$CI-, is followed in time by stimulating the radiative dissociation
of Xe+Cl-. While the formation of Xe+CI- cannot be temporally resolved,the triatomic bond forms in 330fs.
With the advent of femtosecond laser technolo-
gies, real-fime observation of the evolution of chem-
ical reactions, the breaking and making of chemical
bonds, has become a reality (for a review,' see ref.
[ 1] ). Bimolecular reactions represent a particularly
attractive target of such investigations, since they al-
low the study of a complete reaction, allowing the
observation of bond formation between reagents [2 1.