Organic-inorganic hybrid supermolecular building blocks for the design and synthesis of metal-organic materials

Metal-organic materials (MOMs) that contain molecular building blocks (MBBs) or supermolecular building blocks (SBBs) have attracted considerable attention in the field of materials science due to their modular nature and significant permanent porosities, which facilitate the property-studies with respect to gas storage, separation, catalysis and so on. Last two decades have witnessed the extensive development of MBBs approach for design and synthesis of MOMs with desired structures and properties. As an extension of the conventional MBBs approach, the concept of SBBs approach, especially using metal-organic polyhedra (MOPs) as SBBs, was brought forward just eight years ago. However, studies of SBBs approach exhibit significant impacts on the development of MOMs in terms of both design and properties. In this thesis, organic-inorganic hybrid doughnut-like nanostructure (hydoughnuts) and metalcalix( 4)arene complexes were chosen as SBBs for the construction of target-sepecific MOMs. Organic-inorganic hybrid doughnut-like structure (hydoughnut) is an extension of the previous work regarding to organic-inorganic hybrid nanoballs (hyballs). The parent compound, DMA_hydoughnut-1, was synthesized by the self-assembly of polyoxovanadate anions (POVs) and 1,3-benzenedicarboxylate, bdc, linkers. Derivatives of the parent hydoughnut compound can be obtained by changing the counter-ion or by using a variant of bdc (e.g. 5-Br-1,3-bdc) to give rise to DEA_hydoughnut-1 and DMA_hydoughnut-2. Hydoughnut-1 and hydoughnut-2 anions, can serve as SBBs to self-assemble with different metal-organic complexes via O-M-O coordination bonds and/or charge-assisted H-bonds. The resulting three compounds, Mg_hydoughnut-1, Yb_hydoughnut-2 and Dy_hydoughnut-2, were proved to be molecular porous materials (MPMs) because they exhibit permanent surface areas even after losing the crystallinity, indicating the contribution of intrinsic porosity to the gas uptakes. The research that combines calixarene and MOMs enables the extensive study of calixarene-based metal-organic materials (calixMOMs). It is observed that the use of K+-calix(4)arene complexes as SBBs enhance the binding affinity between CO2 molecules and the resultant compound, calixMOM-2, when compared to the parent compound without the complexation of potassium cations (calixMOM-1). Besides the investigation of SBBs with intrinsic porosities for the design and synthesis of MOMs, organocatalytic MOMs (ocMOMs) were also studied in this thesis. Two homochiral organocatalytic MOMs were prepared by using BINOL phosphoric acid as SBBs. The nanoscopic channels in both ocMOMs are lined by organocatalytic chiral phosphoric acid derivatives of BINOL, and ocMOM-1 exhibits improved enantioselectivity over the parent ligand in the transfer hydrogenation of a series of benzoxazines.