Crystalline assembly of metal–organic polyhedra driven by ionic interactions with polyoxometalates

Abstract

Charge-driven self-assembly of cationic zirconium-based metal-organic polyhedra (MOPs) with polyoxometalates (POMs) lead to a series of porous crystalline salts, prepared by simple mixing of soluble precursors. Reactivity of immobilized POMs...

Assembling metal–organic cages as porous materials

“…Some initial studies have shown that this can be achieved by designing mutual coordination bonds between two different cages; 65 using ionic interactions based on charged MOCs to form MOC-based salts; 66 and mixture of charged MOCs with other molecular species such as polyoxometallates. 67 The possibility of forming molecular salts suggests this approach could be applied to other functional ionic components. Additionally, complexity can be integrated into the same cage by using a multivariate linker strategy, where a controlled ligand diversity leads to different photophysical properties.…”

Zirconium Metal–Organic Cages: Synthesis and Applications

“…The chloride anions in HOFs can be replaced by anionic MOCs to form doubly porous salts, which retain high stability and solubility. , The anionic porous cuboctahedral [Cu 24 (SO 3 -bdc) 24 ] 24– cage was employed to stabilize the cationic porous tetrahedral [Zr 12 (μ 3 -O) 4 (μ 2 -OH) 12 (Cp) 12 (Me 2 -bdc) 6 ] 4+ cage, affording a quantitative yield of pure-phase porous salt. The polyoxometalates (POMs) can also be mixed with chloride ions to produce POM-MOC porous salts with enhanced electronic properties …”

“…The polyoxometalates (POMs) can also be mixed with chloride ions to produce POM-MOC porous salts with enhanced electronic properties. 28 Unlike fragile tetrahedral Zr-MOC frameworks that undergo structural rearrangement upon solvent removal, cubic Zr-MOCs with eight SBUs can impart reinforced O−H•••Cl•••H−O interactions and microporosity, resulting in highly stable HOFs. 14 In this aspect, we assembled D-camphoric acid (H 2 D-cam) with zirconocene dichloride to afford a chiral HOF with V 8 E 12 topology (Figure 8).…”

“…Compared to its zirconium-based MOF (Zr-MOF) counterparts, such as the UiO series, Zr-MOCs are similar in structure but with only half the nuclearity . The strong Zr–O bond endows superior characteristics encompassing stability, solubility, and permanent porosity that permit liquid-phase applications. , In this Account, we examine the advances of the Zr-MOC family to date (Scheme ), starting with design strategies of zirconium cages, followed by various synthetic and structural possibilities such as PSM reactions, hydrogen-bonded organic framework (HOFs), ,, and doubly porous salts. − The applications of Zr-MOCs in catalysis, water desalination, biomedical imaging, and gas separation are also discussed to summarize the design ideas that may pave the foundation for future rational designs of Zr-MOCs. Finally, our evaluation of current challenges and prospects are presented.…”

Metal–Organic Polyhedra as Building Blocks for Porous Extended Networks

“…[110] Interestingly, Ohba et al used a similar strategy to demonstrate that bulky counter-ions could be used to control assembly of charged MOPs. [111] They assembled Me 2 -ZrMOP with the polyoxometalates (POMs) of the formula [SiW 12 O 40 ] 4− . Consistent with the charge of each building block, the resultant POM-MOP crystalline assembly has a MOP/POM ratio of 1:1.…”