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Metal‐organic frameworks (MOFs) have attracted significant attention as porous catalyst platforms due to the synthetic modularity of these materials and the diversity of lattice‐confined catalytic active sites that are readily embedded within periodic crystalline frameworks. MOFs offer platforms to heterogenize molecular catalysts, stabilize novel coordination motifs, and leverage confinement effects in catalysis. Crystallinity allows diffraction‐based methods to be employed in the characterization of these catalysts. Access to crystalline MOFs typically requires reversible construction of the metal−ligand (M−L) bonds that connect the SBUs, which provides a mechanism to anneal defects during crystallization. While the required M−L bond reversibility is often promoted by synthesis at elevated temperature, access to crystalline materials based on either transition metals with characteristic slow exchange kinetics or highly basic donor ligands remains a synthetic challenge. Here, we highlight synthetic strategies that leverage M−L exchange kinetics to access MOFs based on kinetically inert ions and extensions of these strategies to the assembly of atomically precise multimetallic materials. [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]

Atomistic control of the coordination environment of lattice ions and the distribution of metal sites within crystalline mixed‐metal coordination polymers remain significant synthetic challenges. Herein is reported the mechanochemical synthesis of a reticular family of crystalline heterobimetallic metal–organic frameworks (MOFs) is now achieved by polymerization of molecular Ru2[II,III] complexes, featuring unprotected carboxylic acid substituents, with Cu(OAc)2. The resulting crystalline heterobimetallic MOFs are solid solutions of Ru2 and Cu2 sites housed within [M3L2] phases. The developed mechanochemical strategy is modular and allows for systematic control of the primary coordination sphere of the Ru2 sites within an isoreticular family of materials. This strategy is anticipated to provide a rational approach to atomically precise mixed‐metal materials. [ABSTRACT FROM AUTHOR]

Atomistic control of the coordination environment of lattice ions and the distribution of metal sites within crystalline mixed‐metal coordination polymers remain significant synthetic challenges. Herein is reported the mechanochemical synthesis of a reticular family of crystalline heterobimetallic metal–organic frameworks (MOFs) is now achieved by polymerization of molecular Ru2[II,III] complexes, featuring unprotected carboxylic acid substituents, with Cu(OAc)2. The resulting crystalline heterobimetallic MOFs are solid solutions of Ru2 and Cu2 sites housed within [M3L2] phases. The developed mechanochemical strategy is modular and allows for systematic control of the primary coordination sphere of the Ru2 sites within an isoreticular family of materials. This strategy is anticipated to provide a rational approach to atomically precise mixed‐metal materials. [ABSTRACT FROM AUTHOR]

The potential to exert atomistic control over the structure of site‐isolated catalyst sites, as well as the topology and chemical environment of interstitial pore spaces, has inspired efforts to apply porous metal‐organic frameworks (MOFs) as catalysts for fine chemical synthesis. In analogy to enzyme‐catalyzed reactions, MOF catalysts have been proposed as platforms in which substrate confinement could be used to achieve chemo‐ and stereoselectivities that are orthogonal to solution‐phase catalysts. In order to leverage the tunable pore topology of MOFs to impact catalyst selectivity, catalysis must proceed at interstitial catalyst sites, rather than at solvent‐exposed interfacial sites. This Minireview addresses challenges inherent to interstitial MOF catalysis by 1) describing the diffusional processes available to sorbates in porous materials, 2) discussing critical factors that impact the diffusion rate of substrates in porous materials, and 3) presenting in operando experimental strategies to assess the relative rates of substrate diffusion and catalyst turnover in MOF catalysis. It is anticipated that the continued development of in operando tools to evaluate substrate diffusion in porous catalysts will advance the application of these materials in fine chemical synthesis. Interfacial or interstitial catalysis? Metal‐organic frameworks (MOFs) have been advanced as catalysts for fine‐chemical synthesis. However, in order to access chemical selectivities that differ from homogenous catalysts, reactions must occur within the pore structure. This Minireview addresses the challenges associated with interstitial MOF catalysis. [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]

The lanthanum-based metal macrocyclic framework, MMCF-3, where the ligand is 1,4,7,10-tetraazacyclododecane-N,N′,N″,N′″-tetra-p-methylbenzoic acid, has been synthesized and characterized by powder X-ray diffraction, single crystal X-ray diffraction, and thermogravimetric analysis. MMCF-3 forms in closely packed 2-D sheets. In MMCF-3, the azamacrocyclic-based ligand coordinates tetradentate to four separate lanthanum ions via its carboxylate groups, leaving the macrocycle site unoccupied. The lanthanum ions are 10-coordinate with a distorted bi-capped square anti-prism coordination environment. The vacancy of the macrocycle site within the framework encourages the utilization of the framework as a cation receptor. The availability of these sites allows for the possibility to coordinate to newly introduced metals to produce heterometallic frameworks, which could exhibit intriguing properties. [ABSTRACT FROM AUTHOR]

Described for the first time is that carbon dioxide (CO2) can be successfully inserted into aryl C−H bonds of the backbone of a metal-organic framework (MOF) to generate free carboxylate groups, which serve as Brønsted acid sites for efficiently catalyzing the methanolysis of epoxides. The work delineates the very first example of utilizing CO2 for heterogeneous C−H activation and carboxylation reactions on MOFs, and opens a new avenue for CO2 chemical transformations under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Described for the first time is that carbon dioxide (CO2) can be successfully inserted into aryl C−H bonds of the backbone of a metal-organic framework (MOF) to generate free carboxylate groups, which serve as Brønsted acid sites for efficiently catalyzing the methanolysis of epoxides. The work delineates the very first example of utilizing CO2 for heterogeneous C−H activation and carboxylation reactions on MOFs, and opens a new avenue for CO2 chemical transformations under mild reaction conditions. [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]

In this review, we systematically summarize our recent work on how metal-organic frameworks (MOFs) are constructed via custom design of organic ligands and beyond. Following a brief introduction of basic concepts and general background of MOFs, we explain how to fine-tune MOFs' structures via the design strategy of network, secondary building unit (SBU), and ligand. Amongst these, the custom design of organic ligands plays a fundamental yet important role in this field. In addition, the custom-designed ligands, which feature certain functional motifs, can further enrich the performances of targeted MOFs owing to the primary functionalities bestowed on the frameworks by the ligands. Therefore, the custom design of organic ligands and beyond can be a useful approach to task-specifical functionalizing of the frameworks. [ABSTRACT FROM AUTHOR]

Crystal engineering of the nbo metal-organic framework (MOF) platform MOF-505 with a custom-designed azamacrocycle ligand (1,4,7,10-tetrazazcyclododecane- N, N′, N′′, N′′′-tetra- p-methylbenzoic acid) leads to a high density of well-oriented Lewis active sites within the cuboctahedral cage in MMCF-2, [Cu2(Cu-tactmb)(H2O)3(NO3)2]. This MOF demonstrates high catalytic activity for the chemical fixation of CO2 into cyclic carbonates at room temperature under 1 atm pressure. [ABSTRACT FROM AUTHOR]

Crystal engineering of the nbo metal-organic framework (MOF) platform MOF-505 with a custom-designed azamacrocycle ligand (1,4,7,10-tetrazazcyclododecane- N, N′, N′′, N′′′-tetra- p-methylbenzoic acid) leads to a high density of well-oriented Lewis active sites within the cuboctahedral cage in MMCF-2, [Cu2(Cu-tactmb)(H2O)3(NO3)2]. This MOF demonstrates high catalytic activity for the chemical fixation of CO2 into cyclic carbonates at room temperature under 1 atm pressure. [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]

Reaction of LnCl3·6H2O with 5-aminotetrazole-1-acetic acid (Hatza) under the presence of KOH produced a set of new Ln(III)/atza complexes, [Ln(atza)2(CH3OH)(H2O)Cl][Ln = Pr (1), Nd (2), Sm (3)], [Ln(atza)2(H2O)3]Cl [Ln = Eu (4), Gd (5)], and [Tb(atza)2(H2O)4]Cl (6). These compounds were structurally characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. The complexes 1−3are isostructural and display two-dimensional frameworks, the isostructural complexes 4−5show one-dimensional (1D) structures, and complex 6forms a 1D framework. Furthermore, the luminescence properties of 4and 6were investigated at room temperature in the solid state. [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]

The design and synthesis of polyhedra using coordination‐driven self‐assembly has been an intriguing research area for synthetic chemists. Metal‐organic polyhedra are a class of intricate molecular architectures that have garnered significant attention in the literature due to their diverse structures and potential applications. Hereby, we report Cu‐MOP, a bifunctional metal‐organic cuboctahedra built using 2,6‐dimethylpyridine‐3,5‐dicarboxylic acid and copper acetate at room temperature. The presence of both Lewis basic pyridine groups and Lewis acidic copper sites imparts catalytic activity to Cu‐MOP for the tandem one‐pot deacetalization‐Knoevenagel/Henry reactions. The effect of solvent system and time duration on the yields of the reactions was studied, and the results illustrate the promising potential of these metal‐organic cuboctahedra, also known as nanoballs for applications in catalysis. [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. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of two new porphyrin-based porous organic polymers (POPs) via Sonogashira cross-coupling reaction and leverage the two obtained POPs is reported for the fabrication of electrochemical aptasensors to detect kanamycin at an ultratrace level. The resultant electrochemical aptasensor demonstrates a high linear relationship with the logarithmic value of kanamycin concentration in the range 5 × 10−5–5 μg/L with the limit of detection of 17.6 pg/L or 36.3 fM. During the analysis of real samples from milk and river, a relative standard deviation of less than 4.39%, and good recovery values in the range 97.0–105% were obtained. [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]

Abstract: Metal–organic frameworks (MOFs) have garnered substantial interest as platforms for site‐isolated catalysis. Efficient diffusion of small‐molecule substrates to interstitial lattice‐confined catalyst sites is critical to leveraging unique opportunities of these materials as catalysts. Understanding the rates of substrate diffusion in MOFs is challenging, and few in situ chemical tools are available to evaluate substrate diffusion during interstitial MOF chemistry. Herein, we demonstrate nitrogen atom transfer (NAT) from a lattice‐confined Ru2 nitride to toluene to generate benzylamine. We use the comparison of the intramolecular deuterium kinetic isotope effect (KIE), determined for amination of a partially deuterated substrate, with the intermolecular KIE, determined by competitive amination of a mixture of perdeuterated and undeuterated substrates, to establish the relative rates of substrate diffusion and interstitial chemistry. We anticipate that the developed KIE‐based experiments will contribute to the development of porous materials for group‐transfer catalysis. [ABSTRACT FROM AUTHOR]

Abstract: Metal–organic frameworks (MOFs) have garnered substantial interest as platforms for site‐isolated catalysis. Efficient diffusion of small‐molecule substrates to interstitial lattice‐confined catalyst sites is critical to leveraging unique opportunities of these materials as catalysts. Understanding the rates of substrate diffusion in MOFs is challenging, and few in situ chemical tools are available to evaluate substrate diffusion during interstitial MOF chemistry. Herein, we demonstrate nitrogen atom transfer (NAT) from a lattice‐confined Ru2 nitride to toluene to generate benzylamine. We use the comparison of the intramolecular deuterium kinetic isotope effect (KIE), determined for amination of a partially deuterated substrate, with the intermolecular KIE, determined by competitive amination of a mixture of perdeuterated and undeuterated substrates, to establish the relative rates of substrate diffusion and interstitial chemistry. We anticipate that the developed KIE‐based experiments will contribute to the development of porous materials for group‐transfer catalysis. [ABSTRACT FROM AUTHOR]

Review: 112 refs. [ABSTRACT FROM AUTHOR]

A microporous Zn-based anionic metal-organic framework (MOF) was synthesized with triangular 4,4′,4′′-(pyridine-2,4,6-triyl)tribenzoic acid. The anionic MOF material featuring open channels proved to be a good capturing agent for the cationic dye methylene blue. In addition, the Zn-MOF demonstrated excellent catalytic activity for CO2 fixation by cycloaddition reaction with epoxides for the generation of cyclic carbonates. [ABSTRACT FROM AUTHOR]

The CoII atom in bis(5-aminotetrazole-1-acetato)tetraaquacobalt(II), [Co(C3H4N5O2)2(H2O)4], (I), is octahedrally coordinated by six O atoms from two 5-aminotetrazole-1-acetate (atza) ligands and four water molecules. The molecule has a crystallographic centre of symmetry located at the CoII atom. The molecules of (I) are interlinked by hydrogen-bond interactions, forming a two-dimensional supramolecular network structure in the ac plane. The CdII atom in catena-poly[[cadmium(II)]-bis(μ-5-aminotetrazole-1-acetato], [Cd(C3H4N5O2)2] n, (II), lies on a twofold axis and is coordinated by two N atoms and four O atoms from four atza ligands to form a distorted octahedral coordination environment. The CdII centres are connected through tridentate atza bridging ligands to form a two-dimensional layered structure extending along the ab plane, which is further linked into a three-dimensional structure through hydrogen-bond interactions. [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]

Abstract: We report an inverse relationship between measurable porosity values and reversible capacity from sucrose-derived hard carbon as an anode for sodium-ion batteries (SIBs). Materials with low measureable pore volumes and surface areas obtained through N2 sorption yield higher reversible capacities. Conversely, increasing measurable porosity and specific surface area leads to sharp decreases in reversible capacity. Utilizing a low porosity material, we thus are able to obtain a reversible capacity of 335mAhg− 1. These findings suggest that sodium-ion storage is highly dependent on the absence of pores detectable through N2 sorption in sucrose-derived carbon. [Copyright &y& Elsevier]

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]

Developing new drugs for the treatment of cancer is of great significance. Coordination compounds based on tetrazole-carboxylates are the potential candidates for cancer treatment. In this article, [Ce2(atzpa)4(H2O)8](NO3)2·2H2O based on 5-aminotetrazole-1-propanoic acid (Hatzpa) and Ce(NO3)3·6H2O has been designed and prepared. Single-crystal X-ray diffraction reveals that the compound is binuclear in which atzpa acts as a bridging ligand. In order to improve the water dispersity of this compound, PEG-5000 (poly (ethyleneglycol-5000)) was coated on [Ce2(atzpa)4(H2O)8](NO3)2·2H2O to prepare the nanoparticles (NPS) in distilled water. In vitro study on HeLa cells shows that Hatzpa is nontoxic itself, while [Ce2(atzpa)4(H2O)8](NO3)2·2H2O NPs show high toxicity. Such NPs have a low half-inhibitory concentration (IC50) of 24lg mL-1 1 (2.0×10-5 M). In addition, such NPs are able to inhibit the migration of HeLa cells even at a low concentration effectively, showing their potential to inhibit the transfer of tumors in vivo. [ABSTRACT FROM AUTHOR]

Isomers sometimes play a fundamental role in the formation of coordination architectures. In this article, bifunctional 5-(n-pyridyl)tetrazole-2-isopropanoic acid (n = 2, 3) has been designed and prepared. Then, reactions of Ca(NO3)2•4H2O with isomeric 5-(n-pyridyl)tetrazole-2- isopropanoic acid (denoted as Hn-pytzipa, n = 2, 3) afforded mononuclear [Ca(2-pytzipa)2(H2O)4] (1) and one-dimensional [Ca(3-pytzipa)2(H2O)2]n (2), respectively. In 1, 2-pytzipa is a bidentate ligand which chelates one Ca(II) via the nitrogen atoms of the pyridine and tetrazole rings while in 2, 3-pytzipa bridges adjacent Ca(II) centers in a μ1,1,3-COO mode. PEG-5000 (poly(ethyleneglycol-5000)) coated [Ca(2-pytzipa)2(H2O)4] (1) and [Ca(3-pytzipa)2(H2O)2]n (2) nanoparticles (NPs) show toxicity towards Hela cells, but the ligands are non-toxic in nature and 2 is superior to 1. Furthermore, cell migration across a 2D artificial gap indicates that both NPs can inhibit the migration of Hela cells. [ABSTRACT FROM AUTHOR]

Abstract: Herein, we report that a new flexible coordination network, NiL2 (L=4‐(4‐pyridyl)‐biphenyl‐4‐carboxylic acid), with diamondoid topology switches between non‐porous (closed) and several porous (open) phases at specific CO2 and CH4 pressures. These phases are manifested by multi‐step low‐pressure isotherms for CO2 or a single‐step high‐pressure isotherm for CH4. The potential methane working capacity of NiL2 approaches that of compressed natural gas but at much lower pressures. The guest‐induced phase transitions of NiL2 were studied by single‐crystal XRD, in situ variable pressure powder XRD, synchrotron powder XRD, pressure‐gradient differential scanning calorimetry (P‐DSC), and molecular modeling. The detailed structural information provides insight into the extreme flexibility of NiL2. Specifically, the extended linker ligand, L, undergoes ligand contortion and interactions between interpenetrated networks or sorbate–sorbent interactions enable the observed switching. [ABSTRACT FROM AUTHOR]

Abstract: Herein, we report that a new flexible coordination network, NiL2 (L=4‐(4‐pyridyl)‐biphenyl‐4‐carboxylic acid), with diamondoid topology switches between non‐porous (closed) and several porous (open) phases at specific CO2 and CH4 pressures. These phases are manifested by multi‐step low‐pressure isotherms for CO2 or a single‐step high‐pressure isotherm for CH4. The potential methane working capacity of NiL2 approaches that of compressed natural gas but at much lower pressures. The guest‐induced phase transitions of NiL2 were studied by single‐crystal XRD, in situ variable pressure powder XRD, synchrotron powder XRD, pressure‐gradient differential scanning calorimetry (P‐DSC), and molecular modeling. The detailed structural information provides insight into the extreme flexibility of NiL2. Specifically, the extended linker ligand, L, undergoes ligand contortion and interactions between interpenetrated networks or sorbate–sorbent interactions enable the observed switching. [ABSTRACT FROM AUTHOR]

Two novel coordination compounds, [Sr(atzp)2(H2O)2]·CH3OH (1) and [Sr(dtzpha)(H2O)3]·4H2O (2) [Hatzp=5-aminotetrazole-1-propionic acid, H2dtzpha=1,3-di(tetrazol-5-yl)benzene-N2,N2′-diacetic acid)], have been generated by using 5-aminotetrazole-1-propionic acid and 1,3-di(tetrazol-5-yl)benzene-N2,N2′-diacetic acid to react with strontium salts, respectively. X-ray diffraction analysis reveals that carboxylic groups of two ligands show the same coordination mode (the μ1,1,3-COO coordination mode), compound 1 displays a 1D structure while compound 2 shows a 2D structure, which implies the influence of the number of the carboxylic acid groups. Luminescence properties of 1 and 2 were investigated at room temperature in the solid state. [ABSTRACT FROM AUTHOR]

Inspiration for molecular design and construction can be derived from mathematically based structures. In the quest for new materials, the adaptation of new building blocks can lead to unexpected results. Towards these ends, the quantitative single-step self-assembly of a shape-persistent, Archimedean-based building block, which generates the largest molecular sphere (a cuboctahedron) that has been unequivocally characterized by synchrotron X-ray analysis, is described. The unique properties of this new construct give rise to a dilution-based transformation into two identical spheres (octahedra) each possessing one half of the molecular weight of the parent structure; concentration of this octahedron reconstitutes the original cuboctahedron. These chemical phenomena are reminiscent of biological fission and fusion processes. The large 6 nm cage structure was further analyzed by 1D and 2D NMR spectroscopy, mass spectrometry, and collision cross-section analysis. New routes to molecular encapsulation can be envisioned. [ABSTRACT FROM AUTHOR]

Inspiration for molecular design and construction can be derived from mathematically based structures. In the quest for new materials, the adaptation of new building blocks can lead to unexpected results. Towards these ends, the quantitative single-step self-assembly of a shape-persistent, Archimedean-based building block, which generates the largest molecular sphere (a cuboctahedron) that has been unequivocally characterized by synchrotron X-ray analysis, is described. The unique properties of this new construct give rise to a dilution-based transformation into two identical spheres (octahedra) each possessing one half of the molecular weight of the parent structure; concentration of this octahedron reconstitutes the original cuboctahedron. These chemical phenomena are reminiscent of biological fission and fusion processes. The large 6 nm cage structure was further analyzed by 1D and 2D NMR spectroscopy, mass spectrometry, and collision cross-section analysis. New routes to molecular encapsulation can be envisioned. [ABSTRACT FROM AUTHOR]

Two novel coordination compounds, namely, [Sm[sub 2](pypza)[sub 2](H[sub 2]O)[sub 10]]Cl[sub 4]·H[sub 2]O (1) and [Eu(pypza)(C[sub 2]O[sub 4])] (2), where pypza=3-(2-pyridyl)-1-pyrazolyl acetato, have been synthesized under hydrothermal conditions. These compounds were characterized by elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction. The X-ray diffraction analysis reveals that compound 1 displays double one-dimensional chains, whereas 2 shows a two-dimensional layer structure via the bridging pypza and oxalate (C[sub 2]O[sub 4][sup 2-]) which may arise from the oxidation of hydroacetic acid through the decomposition and hydrolysis of Hpypza by means of the cleavage of the C-N bond between the carboxylate group and the pyrazolyl ring. Compounds 1 and 2 show three-dimensional networks by hydrogen bonding interactions. Furthermore, the luminescence properties of 1 and 2 have also been investigated at room temperature in the solid state. [ABSTRACT FROM AUTHOR]

Reactions of four different tetrazole-containing carboxylic acids and 4,4'bipyridine with ZnCl2⋅6H2O, produced four new coordination compounds, [Zn(pytza)2(4,4'-bipy)(H2O)2]⋅2H2O (1), (pytza = 5-(3-pyridyl)tetrazole-2-acetato), [Zn(tzpya)2(4,4'-bipy)(H2O)2]⋅8H2O (2) (tzpya = 4-(5-tetrazolyl)pyridine-1-acetato), [Zn(4,4'-bipy)(H2O)4]⋅2(pztza)⋅2H2O (3) (pztza = 5-(2-pyrazinyl)tetrazole-2-acetato). [Zn(atza)2(4,4'-bipy)0.5⋅H2O] (4) (atza = 5-aminotetrazole-1-acetato). These compounds were structurally characterized by elemental analysis, IR spectroscopy, UV-Vis spectroscopy, thermogravimetric analysis and single crystal X-ray diffraction. The X-ray diffraction reveals that compounds 1-3 display 1D polymeric chains while 4 shows a 2D layer structure. Compounds 1-4 are self-assembled to form 3D networks by hydrogen bonding interactions. Furthermore, the luminescent properties were also investigated at room temperature in the solid state. [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]