Reactions of Organic Chemicals

This chapter focuses on the reactions of organic chemicals. The nature of dangerous reactions involving organic chemicals depends on the saturated, unsaturated, or aromatic structures of a particular compound. Saturated hydrocarbons are hardly reactive, especially when they are linear. Branched or cyclic hydrocarbons (especially polycyclic condensed ones) are more reactive, in particular with oxidation reactions. The products are endothermic with ethylenic or acetylenic unsaturated compounds. The reactions, in which a multiple bond plays a role, will be very exothermic and particularly dangerous, especially in the case of the lower ranking and conjugated dienes. In addition, the presence of a multiple bond increases the reactivity of hydrogen atoms in an allylic position. Aromatic compounds possess endothermic character too. Their dangerous reactions will most often involve intermediate or ultimate products, which are highly unstable as in nitration or oxidation. The hydrogen atom in the benzyl position in the aromatic ring is much more reactive. Saturated hydrocarbons are stable. Only cycloalkanes with a tight ring are unstable. Alkenes and alkynes have a strong endothermic character, especially the first homologues and polyunsaturated conjugated hydrocarbons. Apart from a few special cases, the decomposition of unsaturated hydrocarbons requires extreme conditions, which are only encountered in the chemical industry. Polymerization is the logical conclusion because the exact reasons for many accidents of unsaturated hydrocarbons, which are often followed by “spontaneous” detonations, could not always be identified and the distinction between decomposition and polymerization could not always be made.