REACTIONS OF ORGANIC-COMPOUNDS IN EXPLOSIVE-DRIVEN SHOCK-WAVES

Shock waves of 1 mu s duration and peak temperatures from 900 to 1400 K and pressures from 6 to 16 GPa have been applied to measurement of t he rates of a broad spectrum of organic compounds including decomposit ion of explosives. All reaction rates are consistent with known activa tion parameters and reaction conditions, and there is no indication of unique chemical processes connected with the subnanosecond rise time of the shock front. Reactions having both positive and negative activa tion volumes have been studied. Extreme pressure favors ionic reaction mechanisms, whereas extreme temperature favors homolytic mechanisms. Either influence may dominate; thus, cyclohexyl nitrate in benzene giv es cyclohexylbenzene by a reaction of Friedel-Crafts type, whereas neo pentyl nitrate undergoes homolysis, beta-scission, and recombination t o give 2-nitro-2-methylpropane. When methanol is used as a solvent, it ionizes extensively and promotes a variety of reactions which ordinar ily require acid or base catalysis such as ester interchange and addit ion of methanol to olefinic bonds.