FATE OF A HIGHLY STRAINED HYDROCARBON IN AQUEOUS SOIL ENVIRONMENT

Quadricyclane, a highly strained hydrocarbon, is currently being evalu ated by the U.S. Air Force as a possible high-performance aviation fue l. It is therefore important to discover how it would interact with th e environment in the event of a spill. The reactions of quadricyclane were investigated in water, 50/50 wt % water/2-propanol and pure a-pro panol, and in abiotic aqueous soil environments consisting of four dif ferent naturally occurring soils. The reaction products were exo-5-nor bornen-2-ol and nortricyclyl alcohol. The reactions in the three solve nt systems were pseudo-first-order in quadricyclane. Second-order rate constants were determined from plots of the pseudo-first-order rate c onstants versus [H+] and were found to be 26.0 L mol(-1) min(-1) in wa ter, 0.195 L mol(-1) min(-1) in 50/50 water/2-propanol, and 0.099 L mo l(-1) min(-1) in 2-propanol, all at 25 degrees C. The soil experiments were run for periods of up to 9 months. The most important factor aff ecting the reactivity of quadricyclane in the soils was pH, while orga nic matter content was not important. In soils of high pH, quadricycla ne behaved as a light nonaqueous phase liquid except that it had a pro pensity to form microemulsions. In soils of low pH, the reactions prod ucing the alcohols and their subsequent dissolution in the groundwater became significant.