ABSTRACT

This chapter focuses on the type of solid-state reactions in which the solids react directly to form a solid product without intervention of a liquid or vapor phase. Microwave heating is considered a green energy method, because it achieves high temperatures quickly, and the reaction times are generally shortened. Many solid-state reactions are facilitated by using microwave heating. Rearrangement reactions in the solid state are especially of interest, because their occurrence provides support for the mobility of molecules in the solid phase. A classic example is the rearrangement reaction of pinacol to pinacolone under acid catalysis conditions. The mechanism of the pinacolone rearrangement in the solid state was reviewed by Tanaka and Toda. The reaction of the solid pinacol was shown to occur only when its OH groups are properly oriented towards the catalyst. The protonation of the OH groups by the catalyst occurs when their oxygen lone electrons are pointing towards the catalyst, while their hydrogens are pointing away.