LASER-EVAPORATED ALUMINUM ATOM REACTIONS WITH HALOGEN MOLECULES - INFRARED-SPECTRA OF ALX(N) (X=F, CL, BR, I N=1-3) IN SOLID ARGON

Reactions of laser-evaporated aluminum atoms with molecular fluorine, chlorine, bromine, and iodine in excess argon during condensation onto a CsI window at 11 +/- 1 K produced the AIX, (X = F, Cl, Br, I and n = 1-3) and Al(2)X(6) molecules, which were characterized by infrared a bsorption spectroscopy. Low laser power favored the primary reaction p roduct AlX and AlX(2) transient species over the more stable secondary reaction product AlX(3) molecules. Chlorine and bromine isotopic stru ctures substantiated the molecular identifications and vibrational ass ignments. DFT calculations were done for the AlCln and AlBrn series to support the vibrational assignments. Possible Al2Cl4 structures were also explored by DFT calculations, and evidence is presented for a dis torted Cl2AlCl2Al structure. The present study provides further eviden ce for transient aluminum dihalide radicals for the four halogens.