Porous hybrid materials for heterogeneous catalysis and gas storage

A series of new Ru(diphosphine)(diamine)Cl2 complexes with siloxy pendant groups was synthesized and immobilized on mesoporous silica nanoparticles (MSNs) with the hope of generating highly active heterogeneous catalysts by taking advantage of the very large channel diameters (∼2-5 nm) and short diffusion lengths for the substrates as a result of nanoparticle sizes of ∼300-1000 nm. Upon activation with base co-catalysts, these new Ru complexes were highly active for homogeneous asymmetric hydrogenation of ketones and racemic alpha-branched arylaldehydes with enantiomeric excess (ee) up to 94 and 99%, respectively. These Ru complexes were readily immobilized onto several types of MSNs via the siloxy functionalities and the immobilized Ru precatalysts were highly active for the asymmetric hydrogenation of ketones with up to 82% ee and alpha-branched arylaldehydes with ee's of up to 97%.;Highly porous and robust metal organic frameworks (MOFs) were also synthesized for hydrogen storage and for potential use as asymmetric catalysts. 4,8-connected MOFs of the scu topology based on copper paddlewheels and aromatic-rich octa-carboxylic acid bridging ligands were synthesized in order to overcome the tendency of MOFs to undergo framework distortion upon solvent removal. The rigidified MOFs are capable of storing up to 2.5 wt% of H2 at 1 bar (77 K), and 5.5 wt% of H2 at 30 bar (77 K). A series of homochiral porous MOFs were synthesized using bridging ligands containing the chiral BINAP oxide functionalities. The easily accessible catalytic sites make these MOFs interesting candidates for applications in heterogeneous asymmetric catalysis.