Stereoselective Cycloaddition of 1,3-Cyclohexadiene on Si(100): A Simple Algorithm for Product Identification Based on Secondary Orbital Interactions

摘要

We consider the reaction of 1,3-cydohexadiene (1,3-CHD) on Si(lOO) and show that the observed reactivity and stereoselectivity cannot be explained on the basis of thermodynamics. We postulate the existence of secondary orbital interactions (SOIs) and introduce a simple algorithm that examines all possible secondary interactions between the frontier orbitals of the molecule and the surface. We demonstrate using an orbital symmetry-based algorithm supported by DFT calculations that SOIs favor a particular molecular configuration, consistent with the experimental observations. The potential role of SOIs in controlling surface chemical reactions is discussed.