Cycloaddition chemistry of organic molecules with semiconductor surfaces

Recent investigations have shown that cycloaddition reactions, widely used in organic chemistry to form ring compounds, can also be applied to link or ganic molecules to the (001) surfaces of crystalline silicon, germanium, an d diamond. While these surfaces are comprised of Si=Si, Ge=Ge, and C=C stru ctural units that resemble the C=C bonds of organic alkenes, the rates and mechanisms of the surface reactions show some distinct differences from tho se of their organic counterparts This article reviews recent studies of [2 + 2], [4 + 2] Diels-Alder, and other cycloaddition reactions of organic mol ecules with semiconductor surfaces and summarizes the current understanding of the reaction pathways.