Design,Synthesis And Properties Of Crystalline Porous Organic Materials

As a classs of novel crystalline materials,porous organic cages（POCs）and covalent organic frameworks（COFs）have been extensively employed in diverse fields,such as gas adsorption and separation,catalysis,and energy storage,owing to their low density,high porosity,structural uniformity,and ease of functionalization.However,the rational design of crystalline porous organic materials and studying their structure-activity relationships have been proven to be challenging in this research area.Based on the above analysis,a series of fascinating crystalline porous organic materials were designed and synthesized via the Schiff-base condensation reaction according to the dynamic chemistry.Their structures were determined by single crystal and/or powder X-ray diffraction and gas adsorption together with theoretical simulations.We have explored their utilization in asymmetric catalysis and photoredox catalysis.Besides,investigations of the relationship between the structural isomerization/dimensional/degree of interpenetration and properties are also performed.The main contents are as following:1.The tetraaldehyde monomer derived from 5,10-dihydrophenazine was synthesized and condensed with enantiopure 1,2-cyclohexane diamine,and two structural isomers of chiral[4+8]imine organic cages PN-1 and PN-2 were obtained by recrystallization subsequently.PN-1 possesses an unprecedented J₂₆ type geometry,while PN-2 has a tetragonal prism geometry.PN-1R and PN-2R were obtained after the reduction by the Na BH₄,after in situ complexed with Ni²⁺,both could work as highly efficient supramolecular catalysts for asymmetric Michael addition reactions and ee values of the products were up to 92%.PN-2R affords higher reactivity and enantioselectivity than PN-1R,presumably because of PN-2R has large cavity size and open windows that can concentrate reactants and provide much more active sites for the reactions.2.Six isostructural 2D phenazine COFs and one 3D phenazine COF were designed and synthesized based on photoredox 5,10-dihydrophenazine-derived tetraaldehye.Because the 2D porous structure can provide more accessible active sites and enrich the reactants,the 2D COFs displayed higher activity than that of 3D COF in the photocatalytic radical ring-opening polymerization of vinylcyclopropanes（VCPs）monomer,thus allowing the efficient synthesis of poly（VCPs）with controlled molecular weight,low dispersity and high l/c selectivity.Specially,methyoxyl group functionalized 2D COF have the highest activity,probably owing to the enhanced light adsorption and photoinduced electron transfer efficiency.3.The functonalization of the dihydroxy groups of chiral BINOL skeleton generated five tetraaldehyde monomers,which were further condensed with tetrakis（4-aminophenyl）methane（TAM）to produce five chiral covalent organic frameworks（CCOFs）.The obtained CCOF constructed by hydroxyl unmodified BINOL derived aldehyde adopt a five-fold interpenetrated dia topology,while the methyl and ethyl groups functionalzied monomers generated the CCOFs with a four-fold interpenetrated dia topology.For the bulky n-propyl and n-butyl groups modified monoers,the corresponding CCOFs have a non-interpenetrated dia topology.CCOFs with different degrees of interpenetration showed distinct pore characteristics.The pore size and BET surface areas of the non-interpenetrated CCOFs are significantly larger than that of the interpenetrated CCOFs.