*.Current address: Lam Research. 4650 Cushing Parkway, Freemont. CA 94538 * *. Current address: Department of Physics. Washington State University. Pullman, WA 99164

Unsaturated ABSTRACT Unsaturated carbon compounds are unstable at high pressures with respect to denser aggregates. The aggregation reactions can be accelerated by pressure, temperature, photons, and shockwaves. For most compounds, very few details are known about the products, kinetics, and mechanisms of these reactions. We have used several types of absorption, emission and light-scattering spectroscopy to study thermal or photo reactions of cyanogen and naphthalene on the microgram scale in diamond-anvil cells at static pressures to more than 10 gigapascals (GPa). In some cases, products have been recovered for identification by gas chromatography-mass spectroscopy.