Supermolecular Coordination-driven Self-assembly And Property Study Of Vanadium-based Metal-organic Polyhedra

Metal-organic polyhedra(MOPs)are a class of zero-dimensional(0D)discrete molecular entities with clear caged structures that are built from metal parts and organic ligands(niacin,pyridine,or niacin)through coordination-driven self-assembly.Due to their diverse applications in the fields of catalysis,separation,host–guest chemistry,and so on,research interest in MOPs has grown significantly.There are a very few MOPs topologies compared to more than 80,000 MOFs.The reticular chemistry theory of MOPs summarized by Yaghi and O'Keeffe also involves only 14 MOPs topologies.Therefore,the topological blueprint of MOP needs to be expanded urgently.However,the assembly of MOPs is more demanding on components,and SBUs that can be used to build caged structures are extremely scarce compared to MOFs.In addition,most MOPs structures are assembled in a one-step way,compared to step-by-step reactions that can be phased out of intermediates and continue to be pre-designed.Such a complicated self-assembly process indirectly creates challenges and limitations for the construction of MOPs blueprints.With the goal of mimicking spontaneous self-assembly in biomolecule,more complex assembly rules of MOPs still have a lot of room for exploration.Polyoxovanadates(POVs)are considered a kind of potential secondary construction units(SBUs)for assembly MOPs due to their uniqueness and diversity of their coordination models.Herein,under the guidance of reticular chemistry,POVs clusters were adopts as SBUs to assemble the novel MOPs with bidentate or tridentate ligands by coordination-driven self-assembly.12 vanadium-based MOPs were successfully obtained and the properties of ion exchange,catalysis,magnetism and object encapsulation were studied according to their geometric and physical and chemical properties.1.Under solvent thermal conditions,We further expand the POV-based MOPs family.A four-connected(4-c)V5-SBU with a relatively flexible coordination direction was selected and assembled to two types of polyoxovanadate based MOPs with octahedral(oct)and rhombic dodecahedral(rdo)geometries.In addition,compound 2 can be used as a heterogeneous catalyst and exhibits efficient and common catalytic activity for oxidative desulfurization.(H2NMe2)12[(V5O9Cl)6(L1)12][Me OH]11(1)(H2NMe2)12[(V5O9Cl)6(L2)8][Me OH]7(2)L1=anthracene-9,10-dicarboxylic acidL2=3,4,5-tricarboxylate2.Due to the lack of 5-c molecular building blocks(MBBs),the strictly defined Fullerene-like Goldberg polyhedra with the pentagons as extension points is still blank in MOPs.We have successfully isolated a cluster with pentagonal configuration,which can serve as a pentagonal MBB directed assembled to four nanoscale Goldberg MOPs 3-6.Two 32–faced Gv(1,1)MOPs and two 42–faced Gv(2,0)MOPs were formed using linear or triangular organic ligands,respectively.The largest Goldberg MOP 6 has a diameter of up to 4.3 nm,which can capture fullerene C60 molecules in its void cavity.Using single crystal X-ray diffraction technology determined the exact position of the C60 molecules in the crystal lattice.[H₂NMe₂]₂₁[(WV₅O₁₁SO₄)₁₂(BDC)₃₀][W₁₂V₂₀O₉₄]₀.₂₅(3)[H₂NMe₂]₂₁[(WV₅O₁₁SO₄)₁₂(NDC)₃₀][W₁₂V₂₀O₉₄]₀.₂₅(4)[H₂NMe₂]₁₂[(WV₅O₁₁SO₄)₁₂(BTC)₂₀](5)[H₂NMe₂]₁₂[(WV₅O₁₁SO₄)₁₂(TATB)₂₀](6)BDC=1,4-benzenedicarboxylic acid NDC=2,6-naphthalenedicarboxylic acid BTC=1,3,5-benzentricarboxylic acidTATB=4,4',4''-s-triazine-2,4,6-triyl-tribenzoic acid3.Although we have got several advanced structures,it is still not enough to understand this complex assembly principle in depth.Herein,a new 5-c V5-ring SBU was found and four other Gv(2,0)Goldberg MOPs were successfully assembled under the similar solvent thermal conditions.Furthermore,their simplest topology shows the rare trc.Significantly,a dynamically stable intermediate 9 was successfully captured in this complex self-assembly system,that enabled the controlled step-by-step assembly of products during this complex self-assembly process.Magnetic studies have shown that subtle structural changes in molecules are sensitive to magnetism.(H₂NMe₂)₈₄{[V₅O₁₀(SO₄)]₁₂(BTC)₂₀}(7)(H2NMe2)12{[V6O11(SO4)]12(BTC)20}(8)(H2NMe2)48{[V5O10(SO4)]6[V6O11(SO4)]6(BTC)20}(9)(H2NMe2)12{[Mo V5O11(SO4)]12(BTC)20}(10)BTC=1,3,5-benzentricarboxylic acid4.Two equi-size hetero-metal organic polyhedra(MOPs)featuring Platonic and Archimedean solids are nested together into a unique endohedral double-shell cage.Analogous to the principle of the double-shell assembly in virus,the assembly of the nested cage-within-cage structures is based on supramolecular recognition between the inner and the outer shells,and therefore is completely different from the previously reported nested mechanism based on covalent intercage crosslinking.To the best of our knowledge,the unique nested characteristics brand new models for Matryoshka-type assemblies.Moreover,The inner cage can be isolated individually and proves to be a potential molecular receptor to selectively trap guest molecules.(H2NMe2)24{[(V5O9Cl)6(TATB)8][V12O12(TATB)8(HSO4)12]}(11)[(V5O9Cl)6(TATB)8](H2NMe2)12(12)TATB=4,4',4''-s-triazine-2,4,6-triyl-tribenzoic acid...