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The intracellular delivery and functionalization of genetic molecules play critical roles in gene-based theranostics. In particular, the delivery of plasmid DNA (pDNA) with safe nonviral vectors for efficient intracellular gene expression has received increasing attention; however, it still has some limitations. A facile one-pot method is employed to encapsulate pDNA into zeolitic imidazole framework-8 (ZIF-8) and ZIF-8-polymer vectors via biomimetic mineralization and coprecipitation. The pDNA molecules are found to be well distributed inside both nanostructures and benefit from their protection against enzymatic degradation. Moreover, through the use of a polyethyleneimine (PEI) 25 kD capping agent, the nanostructures exhibit enhanced loading capacity, better pH responsive release, and stronger binding affinity to pDNA. From in vitro experiments, the cellular uptake and endosomal escape of the protected pDNA are greatly improved with the superior ZIF-8-PEI 25 kD vector, leading to successful gene expression with high transfection efficacy, comparable to expensive commercial agents. New cost-effective avenues to develop metal-organic-framework-based nonviral vectors for efficient gene delivery and expression are provided., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Hydrogen spillover is an extraordinary effect in heterogeneous catalysis and hydrogen storage, which refers to the surface migration of metal particle-activated hydrogen atoms over the solid supports. Historical studies on this phenomenon have mostly been limited to reducible metal oxides where the long-distance proton-electron coupled migration mechanism has been established, yet the key question remains on how to surmount short-distance and defect-dependent hydrogen migration on nonreducible supports. By demerging hydrogen migration and hydrogenation reaction, here we demonstrate that the hydrogen spillover in nonreducible metal-organic frameworks (MOFs) can be finely modulated by the ligand functional groups or embedded water molecules, enabling significant long-distance (exceed 50 nm) movement of activated hydrogen. Furthermore, using sandwich nanostructured MOFs@Pt@MOFs as catalysts, we achieve highly selective hydrogenation of N-heteroarenes via controllable hydrogen spillover from Pt to MOFs-shell. We anticipate that this work will enhance the understanding of hydrogen spillover and shed light on de novo design of MOFs supported catalysts for many important reactions involving hydrogen. Historical studies on hydrogen spillover have primarily focused on reducible metal oxides, establishing the long-distance proton-electron migration mechanism. This study reveals that in nonreducible metal-organic frameworks, hydrogen spillover can be precisely controlled by ligand functional groups or embedded water molecules, allowing for significant long-distance hydrogen migration. [ABSTRACT FROM AUTHOR]

As an effective method to modulate the physicochemical properties of materials, crystal phase engineering, especially hetero‐phase, plays an important role in developing high‐performance photocatalysts. However, it is still a huge challenge but significant to construct porous hetero‐phase nanostructures with adjustable band structures. As a kind of unique porous crystalline materials, metal–organic frameworks (MOFs) might be the appropriate candidate, but the MOF‐based hetero‐phase is rarely reported. Herein, we developed a secondary building unit (SBU) regulating strategy to prepare two crystal phases of Ti‐MOFs constructed by titanium and 1,4‐dicarboxybenzene, i.e. COK and MIL‐125. Besides, COK/MIL‐125 hetero‐phase was further constructed. In the photocatalytic hydrogen evolution reaction, COK/MIL‐125 possessed the highest H2 yield compared to COK and MIL‐125, ascribing to the Z‐Scheme homojunction at hetero‐phase interface. Furthermore, by decorating with amino groups (i.e. NH2‐COK/NH2‐MIL‐125), the light absorbing capacity was broadened to visible‐light region, and the visible‐light‐driven H2 yield was greatly improved. Briefly, the MOF‐based hetero‐phase possesses periodic channel structures and molecularly adjustable band structures, which is scarce in traditional organic or inorganic materials. As a proof of concept, our work not only highlights the development of MOF‐based hetero‐phase nanostructures, but also paves a novel avenue for designing high‐performance photocatalysts. [ABSTRACT FROM AUTHOR]

Asymmetric hydrogenation, a seminal strategy for the synthesis of chiral molecules, remains largely unmet in terms of activation by non‐metal sites of heterogeneous catalysts. Herein, as demonstrated by combined computational and experimental studies, we present a general strategy for integrating rationally designed molecular chiral frustrated Lewis pair (CFLP) with porous metal–organic framework (MOF) to construct the catalyst CFLP@MOF that can efficiently promote the asymmetric hydrogenation in a heterogeneous manner, which for the first time extends the concept of chiral frustrated Lewis pair from homogeneous system to heterogeneous catalysis. Significantly, the developed CFLP@MOF, inherits the merits of both homogeneous and heterogeneous catalysts, with high activity/enantio‐selectivity and excellent recyclability/regenerability. Our work not only advances CFLP@MOF as a new platform for heterogeneous asymmetric hydrogenation, but also opens a new avenue for the design and preparation of advanced catalysts for asymmetric catalysis. [ABSTRACT FROM AUTHOR]

Oxygen evolution reaction (OER) is an energy‐determined half‐reaction for water splitting and many other energy conversion processes, such as rechargeable metal–air batteries and CO2 reduction, due to its four‐electron sluggish process. To reduce the energy consumption and cost of these advanced technologies, various transition metal‐based nanomaterials, like metal oxides/hydroxides, nitride, and phosphide are synthesized. Among these, metal–organic framework (MOF)‐based materials are considered as the ideal candidate for the fabrication of efficient OER electrocatalysts owing to their unique physicochemical properties. In this review, the fundamental catalytic mechanisms and key evaluation parameters of OER in acidic and alkaline media are presented first. Then, design strategies for MOF‐based OER catalysts and research progress in the study of the structure–performance relationship are summarized. Subsequently, the recent research advances of MOF‐based OER electrocatalysts in alkaline, acidic, and neutral electrolytes are overviewed. Finally, current challenges and future opportunities are provided under the frame of materials design, theoretical understanding, advanced characterization techniques, and industrial applications. [ABSTRACT FROM AUTHOR]

Electrocatalysis is at the heart of many significant chemical transformation processes and advanced clean energy technologies. Traditional noble/transition metal oxides are widely used as electrocatalysts; however, they often suffer from intrinsic disadvantages, including low atom utilization, small surface area, and unfavorable tunability. Metal–organic frameworks (MOFs), as a new family of catalytic materials, are attracting extensive attention due to their unique physicochemical properties. The tremendous pristine MOF‐based materials are created using various synthetic approaches and further used for important energy conversions. Herein, a systematic overview on the unique merits and the state‐of‐the‐art design of MOF‐based electrocatalysts is offered. This review also presents recent advances in the development of various pristine MOFs and MOF‐based host–guest composite catalysts for electrocatalysis (i.e., oxygen reduction reaction, hydrogen oxidation reaction, hydrogen evolution reaction, oxygen evolution reaction, and CO2 reduction reaction) and discusses the future challenges and opportunities in this emerging field. [ABSTRACT FROM AUTHOR]

Selective organic transformations using metal–organic frameworks (MOFs) and MOF-based heterogeneous catalysts have been an intriguing but challenging research topic in both the chemistry and materials communities. Analogous to the reaction specificity achieved in enzyme pockets, MOFs are also powerful platforms for regulating the catalytic selectivity via engineering their catalytic microenvironments, such as metal node alternation, ligand functionalization, pore decoration, topology variation and others. In this review, we provide a comprehensive introduction and discussion about the role of MOFs played in regulating and even boosting the size-, shape-, chemo-, regio- and more appealing stereo-selectivity in organic transformations. We hope that it will be instructive for researchers in this field to rationally design, conveniently prepare and elaborately functionalize MOFs or MOF-based composites for the synthesis of high value-added organic chemicals with significantly improved selectivity. [ABSTRACT FROM AUTHOR]

Direct methane oxidation into value‐added organic oxygenates with high productivity under mild condition remains a great challenge. We show Fe‐O clusters on nodes of metal–organic frameworks (MOFs) with tunable electronic state for direct methane oxidation into C1 organic oxygenates at 50 °C. The Fe‐O clusters are grafted onto inorganic Zr6 nodes of UiO‐66, while the organic terephthalic acid (H2BDC) ligands of UiO‐66 are partially substituted with monocarboxylic modulators of acetic acid (AA) or trifluoroacetic acid (TFA). Experiments and theoretical calculation disclose that the TFA group coordinated with Zr6 node of UiO‐66 enhances the oxidation state of adjacent Fe‐O cluster due to its electron‐withdrawing ability, promotes the activation of C−H bond of methane, and increases its selective conversion, thus leading to the extraordinarily high C1 oxygenate yield of 4799 μmol gcat−1 h−1 with 97.9 % selectivity, circa 8 times higher than those modulated with AA. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: In this work, important commercial pharmaceutical intermediates, phenylpropionic acid compounds, are successfully obtained by catalyzing the reaction of carbon dioxide with phenyl halides using MOF‐5, a typical metal‐organic framework (MOF) material. The influence of temperature, pressure, catalyst type and light on the reaction is investigated, and a 90.3% selectivity towards fluorophenylpropionic acid is reached. Significantly, the catalysts are effective for varied benzyl compounds containing different substituent groups. The catalysts are stable and remain active after three cycles. [ABSTRACT FROM AUTHOR]

Controllable integration of two or more functional components is one of the most convenient and effective ways to obtain composite advanced materials with collective properties and improved performance. In this work, in combination with organic single crystals and metal–organic frameworks (MOFs), a novel 1D well‐defined core–shell heterostructure with single copper phthalocyanine (CuPc) ribbon cores coated with a uniform isoreticular MOF‐3 (IRMOF‐3) shell is successfully constructed. Impressively, thanks to performance the integration and synergy of the CuPc cores and the IRMOF‐3 shells, the sensor devices based on such single heterostructures exhibit outstanding selectivity for NH3 detection at ≈60% relative humidity at room temperature, the current response of which to NH3 is around 34–265 times the magnitude of response to ten potential interfering gases even in the case of the 1:100 concentration ratio of NH3 (5 ppm) and the interfering gases (500 ppm). Moreover, the detection limit of such CuPc@IRMOF‐3 sensors toward NH3 is estimated to be 52 ppb (signal to noise ratio = 3) based on 11 blank determinations, and good stability and reusability can also be achieved. This work highlights that the integration of organic single crystals and MOFs into well‐defined structures offers a new opportunity for high‐performance gas sensors. [ABSTRACT FROM AUTHOR]

Transformation of CO2 into fuels has drawn great attention due to increasing carbon emission in recent years. Coupling metal–organic frameworks (MOFs) with molecular catalysts is a promising technique for boosting the efficiency of carbon dioxide capture and conversion. Herein, a CoTAPc–ZIF-90 hybrid catalyst is synthesized by decorating cobalt phthalocyanine on the outer surface of ZIF-90 through a Schiff base reaction. We demonstrate that the ZIF-90 substrate can cooperate with the cobalt active center to boost the electrocatalytic CO2 reduction performance. CoTAPc–ZIF-90 shows a large current density of 13 mA cm−2 for effective conversion of CO2 into CO in aqueous media at an overpotential of 0.86 V with a faradaic efficiency (FE) of 90%. What's more, the CoTAPc–ZIF-90 hybrid catalyst exhibits significantly higher catalyst stability compared with the free phthalocyanine molecule. [ABSTRACT FROM AUTHOR]

The semihydrogenation of alkynes into alkenes rather than alkanes is of great importance in the chemical industry. Unfortunately, state‐of‐the‐art heterogeneous catalysts hardly achieve high turnover frequencies (TOFs) simultaneously with almost full conversion, excellent selectivity, and good stability. Here, we used metal–organic frameworks (MOFs) containing Zr metal nodes ("UiO") with tunable wettability and electron‐withdrawing ability as activity accelerators for the semihydrogenation of alkynes catalyzed by sandwiched palladium nanoparticles (Pd NPs). Impressively, the porous hydrophobic UiO support not only leads to an enrichment of phenylacetylene around the Pd NPs but also renders the Pd surfaces more electron‐deficient, which leads to a remarkable catalysis performance, including an exceptionally high TOF of 13835 h−1, 100 % phenylacetylene conversion 93.1 % selectivity towards styrene, and no activity decay after successive catalytic cycles. The strategy of using molecularly tailored supports is universal for boosting the selective semihydrogenation of various terminal and internal alkynes. [ABSTRACT FROM AUTHOR]

• The article reviews the recent process in single-site catalysts supported by metal-organic frameworks (MOFs). • The synthesis methods for anchoring single site catalysts on the nodes, ligands or in the nanopores of MOFs are summarized. • The relationship between structure and catalytic performance of single-site catalysts supported by MOFs is explored. • Achievements, challenges and future for single-site catalysts supported by MOFs are discussed. Isolated heterogeneous single-site catalysts have been attracted great interest in diverse catalytic reactions because of their uniform and distinct geometric and electronic structure. Among various porous supports, metal-organic frameworks (MOFs), with molecular level structure control and modularity, offer the versatile platforms for supporting isolated single-site catalysts. Owing to the well-defined anchoring sites lying in the nodes, ligands or nanopores of MOFs, the single-site catalysts could be grafted precisely without protection by bulky ligands. More interestingly, together with the nanopore confinement effect of MOFs, single-site catalysts could exhibit the excellent performances in terms of catalytic activity, selectivity and stability. In this review, we focus on summarizing the recent advances in the precise design, synthesis, characterization and catalytic applications of isolated single-site catalysts supported by MOFs and elucidating the relationship between structure and performance of single-site catalysts. Finally, we give a perspective on controllable synthesis of isolated single-site catalysts supported by MOFs as well as their catalytic applications. [ABSTRACT FROM AUTHOR]

Abstract: Chiral metal–organic framework (CMOF) nanosheets only a few layers thick remain a virgin land waiting for exploration. Herein, the first examples of ultrathin CMOF nanosheets are prepared by the confinement growth of two‐dimensional (2D) chiral layers, which are assembled by helical metal–organic chains within microemulsion. This convenient and easily scaled up inverse microemulsion method gives a series of 2D CMOF nanosheets composed of variable metal nodes or chiral ligands. More significantly, thanks to the exceptionally large number of chiral sites exposed on surfaces, the as‐obtained CMOF nanosheets exhibit much higher enantioselectivity in chiral separation compared with their bulk counterparts. [ABSTRACT FROM AUTHOR]

Abstract: Metal–organic frameworks (MOFs) as selectivity regulators for catalytic reactions have attracted much attention, especially MOFs and metal nanoparticle (NP) shelled structures, e.g., MOFs@NPs@MOFs. Nevertheless, making hydrophilic MOF shells for gathering hydrophobic reactants is challenging. Described here is a new and viable approach employing conjugated micro‐ and mesoporous polymers with iron(III) porphyrin (FeP‐CMPs) as a new shell to fabricate MIL‐101@Pt@FeP‐CMP. It is not only hydrophobic and porous for enriching reactants, but also possesses iron sites to activate C=O bonds, thereby regulating the selectivity for cinnamyl alcohol in the hydrogenation of cinnamaldehyde. Interestingly, MIL‐101@Pt@FeP‐CMPsponge can achieve a high turnover frequency ( 1516.1 h−1), with 97.3 % selectivity for cinnamyl alcohol at 97.6 % conversion. [ABSTRACT FROM AUTHOR]

Of cores! Core–shell Au@metal‐organic‐framework‐5 (MOF‐5) nanoparticles (NPs), in which a single Au NP core is coated with a uniform MOF‐5 shell, were prepared by a facile one‐pot method. The diameter of the Au NP core and the thickness of the MOF‐5 shell are easily tuned by controlling the reaction conditions. These nanoparticles are selective sensors of CO2 in gas mixtures. [ABSTRACT FROM AUTHOR]

Engineering metal-organic frameworks (MOFs) into hierarchical structured materials is crucial for providing a viable platform to construct efficient catalysts and broaden their applications in energy conversion and photocatalysis. Here, a simple and efficient solid-state pyrolysis of Ti-MOFs (NH 2 -MIL-125) sacrificial template combined with a photo-reduction process was developed to construct a series of hierarchical TiO 2 decorated with Pd nanoparticles. The hierarchical TiO 2 inherited the well-defined rounded rectangular submicron-tablet from NH 2 -MIL-125 precursor and was constituted of uniform anatase TiO 2 nanoparticles with an average size of 12 nm. Furthermore, the photocatalytic activity for the hydrogen production from water-methanol solution was improved by the optimization of the content of Pd as a cocatalyst, and the maximum was achieved with a Pd loading of 1.5%. The rate of H 2 evolution of 1.5% Pd decorated hierarchical TiO 2 (1.5% Pd/TiO 2 ) reached to 979.7 μmol h −1 and 112.7 μmol h −1 , under UV–vis light and simulated solar light, respectively. This unusual photocatalytic activity may be resulted from the positive synergetic effect of efficient light absorption, promoted separation and migration of photo-induced electron-hole carriers. The work highlights the potential of the MOFs-based hierarchical TiO 2 in the photocatalytic water splitting under solar light. [ABSTRACT FROM AUTHOR]

• The mechanisms for chiral resolution are introduced. • Synthesis and regulation of chiral pores in the innovative porous materials are reviewed. • Recent developments for chiral resolution by porous materials are summarized. • The remained challenges and perspectives in this field are also discussed. Chirality is well known as a ubiquitous feature for the sustainability of life in nature. For instance, chiral substances with pure enantiomeric forms are essential for the generation and evolution of life. Therefore, the chiral separation of enantiomers is of great significance in both life science and pharmaceutical industry. The two most widely adopted chiral separation strategies are chromatographic separation and membrane-assisted separation, the latter one of which is promising for large-scale production due to its potential advantages. In this review, we summarized the innovative materials with intrinsic micropores developed in recent years and their application for chiral resolution either as stationary phases in chromatography or as separation membranes, including metal organic frameworks (MOFs), covalent organic frameworks (COFs), modified graphene or graphene-oxides (GO), porous organic cages (POCs) and others. [ABSTRACT FROM AUTHOR]