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MIL-53 represents one of the most notable metal–organic frameworks given its unique structural flexibility and remarkable thermal stability. In this study, a shaker-type ball milling method has been developed into a facile and generalizable synthetic strategy to access a family of MIL-53 type materials under ambient conditions. During the explorations of [M(OH)(fumarate)] (M = Al, Ga, and In), we report a positive correlation between the metal–ligand (M–L) bond reversibility and the size of resultant crystallites under the mechanochemical process. The more kinetically labile the M–L bond is, the larger the afforded crystallite size is. [ABSTRACT FROM AUTHOR]

We report a synthetic strategy to integrate discrete coordination cages into extended porous materials by decorating opposite charges on the singular cage, which offers multidirectional electrostatic forces among cages and leads to a porous supramolecular ionic solid. The resulting material is non-centrosymmetric and affords a piezoelectric coefficient of 8.19 pC N−1, higher than that of the wurtzite ZnO. [ABSTRACT FROM AUTHOR]

Methods to incorporate kinetically inert metal nodes and highly basic ligands into single-crystalline metal–organic frameworks (MOFs) are scarce, which prevents synthesis and systematic variation of many potential heterogeneous catalyst materials. Here we demonstrate that metallopolymerization of kinetically inert Ru2 metallomonomers via labile Ag–N bonds provides access to a family of atomically precise single-crystalline Ru2-based coordination polymers with varied network topology and primary coordination sphere. [ABSTRACT FROM AUTHOR]

A new porous metal–metalloporphyrin framework, MMPF-10, has been constructed from an octatopic porphyrin ligand, which links copper paddlewheel units to form a framework with fmj topology. In situ metallation of the porphyrin ligands provides MMPF-10 with two unique accessible Cu(ii) centers. This allows it to behave as an efficient Lewis acid catalyst in the first reported reaction of CO2 with aziridines to synthesize oxazolidinones catalyzed by an MMPF. [ABSTRACT FROM AUTHOR]

Framework fragility upon the removal of guest solvent molecules has remained an issue for a substantial amount of metal–organic frameworks (MOFs). To address this issue, in this work we illustrate a strategy for the introduction of size-matching ligands as braces that are deliberately anchored onto the open metal sites to support and segment the pores thereby boosting the framework robustness. This is exemplified by employing 4,4′-bipyridine as a brace to bridge two trigonal prismatic clusters of Co3(μ3-O)(COO)6, generating a robust MOF that exhibits permanent porosity and selective gas adsorption behaviors. [ABSTRACT FROM AUTHOR]

Two rht-type metal–organic frameworks (MOFs) based upon the tetrazolate moiety and pyrazolate moiety, respectively, have been investigated for carbon dioxide (CO2) adsorption and selective adsorption of CO2 over CH4, which shows that the rht-MOF featuring the pyrazolate moiety demonstrates superior performances compared to the rht-MOF based on the tetrazolate moiety. In spite of more exposed nitrogen atoms in the tetrazolate-based rht-MOF, the counter-intuitive observations of CO2 capture in the two rht-MOFs were interpreted by computational studies, which reveal that the local electric field favours more than the richness of exposed nitrogen atoms for the interactions with CO2 molecules. [ABSTRACT FROM AUTHOR]

A family of soluble organic–inorganic hybrid doughnut-like anions, hydoughnuts, has been prepared by the self-assembly of polyoxovanadate anions and 1,3-benzenedicarboxylate (bdc) linkers. Derivatives of the parent hydoughnut, [(V4O8Cl)4(bdc)8]4−, can be obtained by changing the counter-ion or by using a variant of bdc. [ABSTRACT FROM AUTHOR]

It has now been demonstrated that Ru(ii)tris(2,2′-bipyridine) (RuBpy) can be utilized to template the formation of new metal organic framework (MOF) materials containing crystallographically resolved RuBpy clusters with unique photophysical properties. Two such materials, RWLC-1 and RWLC-2, have now been reported from our laboratory and are composed of RuBpy encapsulated in MOFs composed of Zn(ii) ions and 1,3,5-tris(4-carboxyphenyl)benzene ligands (C. L. Whittington, L. Wojtas and R. W. Larsen, Inorg. Chem., 2014, 53, 160–166). Here, a third RuBpy templated photoactive MOF is described (RWLC-3) that is derived from the reaction between Zn(ii) ions and 1,4-dicarboxybenzene in the presence of RuBpy. Single Crystal X-ray diffraction studies determined the position of RuBpy cations within the crystal lattice. The RWLC-3 structure is described as a 2-fold interpenetrated pillared honeycomb network (bnb) containing crystallographically resolved RuBpy clusters. The two bnb networks are weakly interconnected. The encapsulated RuBpy exhibits two emission decay lifetimes (τ-fast = 120 ns, τ-slow = 453 ns) and a bathochromic shift in the steady state emission spectrum relative to RuBpy in ethanol. [ABSTRACT FROM AUTHOR]

Two rare indium-based porous metal–metalloporphyrin frameworks (MMPFs), MMPF-7 and MMPF-8, were constructed by self-assembly of In(iii) and two custom-designed porphyrin–tetracarboxylate ligands. MMPF-7 and MMPF-8 possess the pts topology and exhibit interesting CO2 adsorption properties. [ABSTRACT FROM AUTHOR]

A series of prototypal metal–organic frameworks (MOFs) consisting of polyhedral cages with accessible Lewis-acid sites, have been systematically investigated for Friedländer annulation reaction, a straightforward approach to synthesizing quinoline and its derivatives. Amongst them MMCF-2 demonstrates significantly enhanced catalytic activity compared with the benchmark MOFs, HKUST-1 and MOF-505, as a result of a high-density of accessible Cu(ii) Lewis acid sites and large window size in the cuboctahedral cage-based nanoreactor of MMCF-2. [ABSTRACT FROM AUTHOR]

A strategy for building highly connected robust MOFs from linear ligands is exemplified by the construction of MTAF-4, a rare (6,9)-connected MOF, based on the custom-designed bifunctional linear ligand, 4-(1,2,3-triazol-4-yl)-benzoate, that connects two types of highly connected zinc cluster moieties generated in situ. MTAF-4 is robust and permanently microporous and is capable of adsorbing CO2, H2 and CH4 under high pressures. [ABSTRACT FROM AUTHOR]

Pre-introducing an extra carbon source into the porous aromatic framework of PAF-1 followed by thermolysis affords a new microporous carbon material, which demonstrates a CO2 uptake capacity of 93 cm3 g−1 (equivalent to 4.1 mmol g−1 or 18.2 wt%) at 295 K and 1 bar. [ABSTRACT FROM AUTHOR]

Two homochiral organocatalytic MOMs were prepared using tetra- and octa-carboxylate ligands, respectively. The nanoscopic channels in these MOMs are lined by organonocatalytic chiral phosphoric acid derivatives of binol and ocMOM-1 exhibited improved enantioselectivity over the parent ligand in the context of transfer hydrogenation of a series of benzoxazines. [ABSTRACT FROM AUTHOR]

MIL-53 represents one of the most notable metal-organic frameworks given its unique structural flexibility and remarkable thermal stability. In this study, a shaker-type ball milling method has been developed into a facile and generalizable synthetic strategy to access a family of MIL-53 type materials under ambient conditions. During the explorations of [M(OH)(fumarate)] (M = Al, Ga, and In), we report a positive correlation between the metal-ligand (M-L) bond reversibility and the size of resultant crystallites under the mechanochemical process. The more kinetically labile the M-L bond is, the larger the afforded crystallite size is.

Methods to incorporate kinetically inert metal nodes and highly basic ligands into single-crystalline metal-organic frameworks (MOFs) are scarce, which prevents synthesis and systematic variation of many potential heterogeneous catalyst materials. Here we demonstrate that metallopolymerization of kinetically inert Ru2 metallomonomers via labile Ag-N bonds provides access to a family of atomically precise single-crystalline Ru2-based coordination polymers with varied network topology and primary coordination sphere.

Evaluation of the potential for metal-metal (M-M) cooperation to enable catalysis requires access to specific polynuclear aggregates that display appropriate geometry and size. In many cases, exerting synthetic control over the aggregation of simple metal salts is a challenge. For example, Pd(ii) acetate self assembles as a trimer ( i.e. Pd 3 (OAc) 6 ) both in the solid state and in solution and does not feature close Pd-Pd interactions. Related carboxylate-supported Pd 2 aggregates ( i.e. Pd 2 (OAc) 4 ), which would feature close Pd-Pd interactions, are thermodynamically metastable in solution phase and thus largely unavailable. Here we demonstrate ion metathesis within pre-formed metal-organic frameworks (MOFs) to prepare metastable Pd 2 tetracarboxylates sites. The newly synthesized materials are characterized by elemental analysis, PXRD, SCXRD, EXAFS, XANES, and gas adsorption analysis. In addition, the critical role of network solvation on the kinetics of ion metathesis was revealed by coupled TGA-MS and ICP-MS experiments. The demonstration of templated ion metathesis to generate specific metastable coordination sites that are inaccessible in solution phase chemistry represents a new opportunity to interrogate the chemistry of specific polynuclear metal aggregates.

A new porous metal-metalloporphyrin framework, MMPF-10, has been constructed from an octatopic porphyrin ligand, which links copper paddlewheel units to form a framework with fmj topology. In situ metallation of the porphyrin ligands provides MMPF-10 with two unique accessible Cu(ii) centers. This allows it to behave as an efficient Lewis acid catalyst in the first reported reaction of CO 2 with aziridines to synthesize oxazolidinones catalyzed by an MMPF.

Two rht-type metal-organic frameworks (MOFs) based upon the tetrazolate moiety and pyrazolate moiety, respectively, have been investigated for carbon dioxide (CO2) adsorption and selective adsorption of CO2 over CH4, which shows that the rht-MOF featuring the pyrazolate moiety demonstrates superior performances compared to the rht-MOF based on the tetrazolate moiety. In spite of more exposed nitrogen atoms in the tetrazolate-based rht-MOF, the counter-intuitive observations of CO2 capture in the two rht-MOFs were interpreted by computational studies, which reveal that the local electric field favours more than the richness of exposed nitrogen atoms for the interactions with CO2 molecules.

It has now been demonstrated that Ru(ii)tris(2,2'-bipyridine) (RuBpy) can be utilized to template the formation of new metal organic framework (MOF) materials containing crystallographically resolved RuBpy clusters with unique photophysical properties. Two such materials, RWLC-1 and RWLC-2, have now been reported from our laboratory and are composed of RuBpy encapsulated in MOFs composed of Zn(ii) ions and 1,3,5-tris(4-carboxyphenyl)benzene ligands (C. L. Whittington, L. Wojtas and R. W. Larsen, Inorg. Chem., 2014, 53, 160-166). Here, a third RuBpy templated photoactive MOF is described (RWLC-3) that is derived from the reaction between Zn(ii) ions and 1,4-dicarboxybenzene in the presence of RuBpy. Single Crystal X-ray diffraction studies determined the position of RuBpy cations within the crystal lattice. The RWLC-3 structure is described as a 2-fold interpenetrated pillared honeycomb network (bnb) containing crystallographically resolved RuBpy clusters. The two bnb networks are weakly interconnected. The encapsulated RuBpy exhibits two emission decay lifetimes (τ-fast = 120 ns, τ-slow = 453 ns) and a bathochromic shift in the steady state emission spectrum relative to RuBpy in ethanol.

Self-assembly of the custom-designed octatopic porphyrin ligand of tetrakis(3,5-dicarboxybiphenyl)porphine with the in situ generated Cu2(CO2)4 paddlewheel moieties afforded a porous metal-metalloporphyrin framework, MMPF-9, which features a high density of Cu(II) sites confined within nanoscopic channels and demonstrates excellent performances as a heterogeneous Lewis-acid catalyst for chemical fixation of CO2 to form carbonates at room temperature under 1 atm pressure.

Pre-introducing an extra carbon source into the porous aromatic framework of PAF-1 followed by thermolysis affords a new microporous carbon material, which demonstrates a CO2 uptake capacity of 93 cm(3) g(-1) (equivalent to 4.1 mmol g(-1) or 18.2 wt%) at 295 K and 1 bar.

The replacement of the pillar ligand, 4,4'-bipyridine, in the prototypal pillared MOF, MOF-508, with the custom-designed ligand, 4,4'-(2H-1,2,3-triazole-2,4-diyl)dipyridine, affords a porous metal-triazolate framework, MTAF-3, which demonstrates remarkable enhancement of CO(2) uptake capacity by a factor of ~3 compared to the parent MOF-508.

A porous metal-metalloporphyrin framework, MMPF-2, has been constructed from a custom-designed octatopic porphyrin ligand, tetrakis(3,5-dicarboxyphenyl)porphine, that links a distorted cobalt trigonal prism secondary building unit. MMPF-2 possesses permanent microporosity with the highest surface area of 2037 m(2) g(-1) among reported porphyrin-based MOFs, and demonstrates a high uptake capacity of 170 cm(3) g(-1) CO(2) at 273 K and 1 bar.