Surface chiral self-dimerization

This chapter focuses on several recent topics of novel catalyst design with metal complexes on oxide surfaces for selective catalysis, such as stQbene epoxidation, asymmetric BINOL synthesis, shape-selective aUcene hydrogenation and selective benzene-to-phenol synthesis, which have been achieved by novel strategies for the creation of active structures at oxide surfaces such as surface isolation and creation of unsaturated Ru complexes, chiral self-dimerization of supported V complexes, molecular imprinting of supported Rh complexes, and in situ synthesis of Re clusters in zeolite pores (Figure 10.1). 

Chiral Self-Dimerization ofV Complexes on a S/O2 Surface for Asymmetric Catalysis 383... 

Chiral Self-Dimerization of V Complexes on a SiOj Surface for Asymmetric Catalysis... 

The chiral self-dimerization oftheV complex precursors at the Si02 surface produced a unique reaction space for the selective oxidation. 

Alkylated HBCs form regular monolayers on the HOPG surface in solution and asymmetric 7/V characteristics were measured by STS [34b]. This diode-like effect has been attributed to positional asymmetry of either the vertical placement of the disc in the gap or of the frontier molecular orbitals relative to the electrodes. The alkylphenyl substituted HBCs self-assemble into 2D crystals of the discs with variable vertical displacements from the substrate [93]. When the alkylphenyl chains contain chiral centers, a regular staircase superstructure results. A submolecular visualization of a covalently linked HBC dimer on the HOPG surface revealed a contrast, which reflects the structure of the aromatic parts of the molecule, with the aromatic moieties being oriented like graphene layers in graphite (Fig. 3.25) [94]. 

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