Stepwise Amplification of Circularly Polarized Luminescence in Chiral Metal Cluster Ensembles

Chiral metal-organic frameworks (MOFs) are usually endowed by chiral linkers and/or guests. The strategy using chiral secondary building units in MOFs for solving the trade-off of circularly polarized luminescence (CPL)-active materials, high photoluminescence quantum yields (PLQYs) and high dissymmetry factors (|g_lum |) has not been demonstrated. This work directionally assembles predesigned chiral silver clusters with ACQ linkers through reticular chemistry. The nanoscale chirality of the cluster transmits through MOF's framework, where the linkers are arranged in a quasi-parallel manner and are efficiently isolated and rigidified. Consequently, this backbone of chiral cluster-based MOFs demonstrates superb CPL, high PLQYs of 50.3%, and |g_lum | of 1.2 × 10^-2 . Crystallographic analyses and DFT calculations show the quasi-parallel arrangement manners of emitting linkers leading to a large angle between the electric and magnetic transition dipole moments, boosting CPL response. As compared, an ion-pair-direct assembly without interactions between linkers induces one-ninth |g_lum | and one-sixth PLQY values, further highlighting the merits of directional arrangement in reticular nets. In addition, a prototype CPL switching fabricated by a chiral framework is controlled through alternating ultraviolet and visible light. This work is expected to inspire the development of reticular chemistry for high-performance chiroptical materials.

Twisting of Porphyrin by Assembly in a Metal-Organic Framework yielding Chiral Photoconducting Films for Circularly-Polarized-Light Detection

While materials based on organic molecules usually have either superior optoelectronic or superior chiral properties, the combination of both is scarce. Here, a crystalline chiroptical film based on porphyrin with homochiral side groups is presented. While the dissolved molecule has a planar, thus, achiral porphyrin core, upon assembly in a metal-organic framework (MOF) film, the porphyrin core is twisted and chiral. The close packing and the crystalline order of the porphyrin cores in the MOF film also results in excellent optoelectronic properties. By exciting the Soret band of porphyrin, efficient photoconduction with a high On-Off-ratio is realized. More important, handedness-dependent circularly-polarized-light photoconduction with a dissymmetry factor g of 4.3×10^-4 is obtained. We foresee the combination of such assembly-induced chirality with the rich porphyrin chemistry will enable a plethora of organic materials with exceptional chiral and optoelectronic properties.

One-Dimensional Helical Nanostructures from the Hierarchical Self-Assembly of an Achiral "Rod-Coil" Alternating Copolymer

The self-assembly of alternating copolymers (ACPs) has attracted considerable interest due to their unique alternating nature. However, compared with block copolymers, their self-assembly behavior has remained much less explored and their reported self-assembled structures are limited. Here, we report the formation of supramolecular helical structures by the self-assembly of an achiral rod-coil alternating copolymer, poly(quarter(3-hexylthiophene)-alt-poly(ethylene glycol)) (P(Q3HT-alt-PEG)). The copolymer exhibited an interesting hierarchical self-assembly process, driven by the π-π stacking of the Q3HT segments and the solvophobic interaction of the alkyl chains in tetrahydrofuran (THF)-isopropanol (iPrOH) mixed solvents. The copolymer first self-assembled into thin nanobelts with a uniform size, then grew to helical nanoribbons and eventually twisted into helical nanowires with an average diameter of 25 ± 9 nm and a mean pitch of 80 ± 10 nm. Dissipative particle dynamics (DPD) simulation supported the formation course of the helical nanowires. Furthermore, the addition of (S)-ethyl lactate and (R)-ethyl lactate in the self-assembly of P(Q3HT-alt-PEG) resulted in the formation of left-handed and right-handed chiral nanowires, respectively, demonstrating the tunability of the chirality of the helical wires. This study expands the library of ordered self-assembled structures of ACPs, and also brings a new strategy and mechanism to construct helical supramolecular structures. This article is protected by copyright. All rights reserved.

Avoiding the Center-Symmetry Trap: Programmed Assembly of Dipolar Precursors into Porous, Crystalline Molecular Thin Films

Liquid-phase, quasi-epitaxial growth is used to stack asymmetric, dipolar organic compounds on inorganic substrates, permitting porous, crystalline molecular materials that lack inversion symmetry. This allows material fabrication with built-in electric fields. A new programmed assembly strategy based on metal-organic frameworks (MOFs) is described that facilitates crystalline, noncentrosymmetric space groups for achiral compounds. Electric fields are integrated into crystalline, porous thin films with an orientation normal to the substrate. Changes in electrostatic potential are detected via core-level shifts of marker atoms on the MOF thin films and agree with theoretical results. The integration of built-in electric fields into organic, crystalline, and porous materials creates possibilities for band structure engineering to control the alignment of electronic levels in organic molecules. Built-in electric fields may also be used to tune the transfer of charges from donors loaded via programmed assembly into MOF pores. Applications include organic electronics, photonics, and nonlinear optics, since the absence of inversion symmetry results in a clear second-harmonic generation signal.

Chiral Resolution of Spin-Crossover Active Iron(II) [2x2] Grid Complexes

Chiral magnetic materials are proposed for applications in second‐order non‐linear optics, magneto‐chiral dichroism, among others. Recently, we have reported a set of tetra‐nuclear Fe(II) grid complex conformers with general formula C/S‐[Fe₄L₄]⁸⁺ (L: 2,6‐bis(6‐(pyrazol‐1‐yl)pyridin‐2‐yl)‐1,5‐dihydrobenzo[1,2‐d : 4,5‐d′]diimidazole). In the grid complexes, isomerism emerges from tautomerism and conformational isomerism of the ligand L, and the S‐type grid complex is chiral, which originates from different non‐centrosymmetric spatial organization of the trans type ligand around the Fe(II) center. However, the selective preparation of an enantiomerically pure grid complex in a controlled manner is difficult due to spontaneous self‐assembly. To achieve the pre‐synthesis programmable resolution of Fe(II) grid complexes, we designed and synthesized two novel intrinsically chiral ligands by appending chiral moieties to the parent ligand. The complexation of these chiral ligands with Fe(II) salt resulted in the formation of enantiomerically pure Fe(II) grid complexes, as unambiguously elucidated by CD and XRD studies. The enantiomeric complexes exhibited similar gradual and half‐complete thermal and photo‐induced SCO characteristics. The good agreement between the experimentally obtained and calculated CD spectra further supports the enantiomeric purity of the complexes and even the magnetic studies. The chiral resolution of Fe(II)‐ [2×2] grid complexes reported in this study, for the first time, might enable the fabrication of magneto‐chiral molecular devices.

Surface-Mounted Metal-Organic Frameworks: Past, Present, and Future Perspectives

Metal-organic frameworks (MOFs) are an emerging class of porous materials composed of organic linkers and metal centers/clusters. The integration of MOFs onto the solid surface as thin films/coatings has spurred great interest, thanks to leveraging control over their morphology (such as size- and shape-regulated crystals) and orientation, flexible processability, and easy recyclability. These aspects, in synergy, promise a wide range of applications, including but not limited to gas/liquid separations, chemical sensing, and electronics. Dozens of innovative methods have been developed to manipulate MOFs on various solid substrates for academic studies and potential industrial applications. Among the developed deposition methods, the liquid-phase epitaxial layer-by-layer (LPE-LbL) method has demonstrated its merits over precise control of the thickness, roughness, homogeneity, and orientations, among others. Herein, we discuss the major developments of surface-mounted MOFs (SURMOFs) in LbL process optimization, summarizing the SURMOFs' performance in different applications, and put forward our perspective on the future of SURMOFs in terms of advances in the formulation, applications, and challenges. Finally, future prospects and challenges with respect to SURMOFs growth will be discussed, keeping the focus on their widening applications.

Chirality Remote Control in Nanoporous Materials by Circularly Polarized Light

The ability to dynamically control chirality remains a grand challenge in chemistry. Although many molecules possess chiral isomers, lacking their isolation, for instance during photoisomerization, results in racemic mixtures with suppressed enantiospecific chiral properties. Here, we present a nanoporous solid in which chirality and enantioselective enrichment is induced by circularly polarized light (CPL). The material is based on photoswitchable fluorinated azobenzenes attached to the scaffold of a crystalline metal-organic framework (MOF). The azobenzene undergoes trans-to-cis-photoisomerization upon irradiation with green light and reverts back to trans upon violet light. While each moiety in cis conformation is chiral, we show the trans isomer also possesses a nonplanar, chiral conformation. During photoisomerization with unpolarized light, no enantiomeric enrichment is observed and both isomers, R- and S-cis as well as R- and S-trans, respectively, are formed in identical quantities. In contrast, CPL causes chiral photoresolution, resulting in an optically active material. Right-CPL selectively excites R-cis and R-trans enantiomers, producing a MOF with enriched S-enantiomers, and vice versa. The induction of optical activity is reversible and only depends on the light-handedness. As shown by first-principle DFT calculations, while both, trans and cis, are stabilized in nonplanar, chiral conformations in the MOF, the trans isomer adopts a planar, achiral form in solution, as verified experimentally. This shows that the chiral photoresolution is enabled by the linker reticulation in the MOF. Our study demonstrates the induction of chirality and optical activity in solid materials by CPL and opens new opportunities for chiral resolution and information storage with CPL.

Chiral Detection with Coordination Polymers

Coordination polymers and metal-organic frameworks are prime candidates for general chemical sensing, but the use of these porous materials as chiral probes is still an emerging field. In the last decade, they have found application in a range of chiral analysis methods, including liquid- and gas-phase chromatography, circular dichroism spectroscopy, fluorescence sensing, and NMR spectroscopy. In this minireview, we examine recent works on coordination polymers as chiral sensors and their enantioselective host-guest chemistry, while highlighting their potential for application in different settings.

Controlled Two-Dimensional Alignment of Metal-Organic Frameworks in Polymer Films

Controlling the alignment of metal-organic framework (MOF) particles is valueable for fully exploiting the anisotropic properties and porous structure of these materials. Herein, we propose a simple, one-step method that can control the two-dimensional (2D) alignment of MOF particles over large areas. Orientational control is achieved without consideration of the underlying lattice parameters or the need for particle surface modification, but instead was achieved by selection of the casting solvent on a water surface. Two distinct types of MOF particles, a hexagonal bifrustum morphology of MIL-96 and an octahedral morphology of the UiO-66 family were aligned and captured in a polydimethylsiloxane (PDMS) matrix using this approach. This work provides opportunities for studying and utilizing the anisotropic properties of MOFs in thin film applications.

In Situ Spectroscopy of Calcium Fluoride Anchored Metal-Organic Framework Thin Films during Gas Sorption

Surface‐mounted metal–organic frameworks (SURMOFs) show promising behavior for a manifold of applications. As MOF thin films are often unsuitable for conventional characterization techniques, understanding their advantageous properties over their bulk counterparts presents a great analytical challenge. In this work, we demonstrate that MOFs can be grown on calcium fluoride (CaF₂) windows after proper functionalization. As CaF₂ is optically (in the IR and UV/Vis range of the spectrum) transparent, this makes it possible to study SURMOFs using conventional spectroscopic tools typically used during catalysis or gas sorption. Hence, we have measured HKUST‐1 during the adsorption of CO and NO. We show that no copper oxide impurities are observed and also confirm that SURMOFs grown by a layer‐by‐layer (LbL) approach possess Cu⁺ species in paddlewheel confirmation, but 1.9 times less than in bulk HKUST‐1. The developed methodology paves the way for studying the interaction of any adsorbed gases with thin films, not limited to MOFs, low temperatures, or these specific probe molecules, pushing the boundaries of our current understanding of functional porous materials.

N-Heterocyclic Carbene as a Surface Platform for Assembly of Homochiral Metal-Organic Framework Thin Films in Chiral Sensing

N-heterocyclic carbenes (NHCs) have attracted increasing attention on surface assembly due to their strong metal binding property, but an NHC-modified metal surface as a new growth platform to assemble other functional materials is still a challenge. Here, we report the preparation and chiral sensing properties of homochiral metal-organic framework thin films on carboxyl-containing NHC self-assembled monolayer-modified gold (Au(NHC)) substrates. By using a liquid-phase epitaxial layer-by-layer method, enantiopure [Cu₂(cam)₂dabco]_n thin films with preferred [110] crystal orientation have been successfully grown on Au(NHC) surfaces. The results of electrochemical cyclic voltammetry and quartz crystal microbalance uptakes of (R)- and (S)-1-phenylethanol show that the chiral porous thin film on the robust Au(NHC) surface has good enantiomeric electrochemical recognition and enantioselective adsorption. The present work is a new step to develop metal-NHCs as surface platforms for the preparation of multifunctional thin films for sensing applications.

Surface-coordinated metal-organic framework thin films (SURMOFs) for electrocatalytic applications

The design and development of highly efficient electrocatalysts are very important in energy storage and conversion. As a kind of inorganic organic hybrid material, metal-organic frameworks (MOFs) have been used as electrocatalysts in electrocatalytic reactions due to their structural diversities and fascinating functionalities. Particularly, MOF thin films are coordinated on substrate surfaces by a liquid phase epitaxial (LPE) layer by layer (LBL) growth method (called surface-coordinated MOF thin films, SURMOFs), and recently have been studied in various applications due to their precisely controlled thickness, preferred growth orientation and homogeneous surface. In this review, we will summarize the preparation and electrocatalysis of SURMOFs and their derived thin films (SURMOF-D). The SURMOF based thin films possess diverse topological structures and flexible properties, providing abundant catalytically active sites and fast charge transfer for efficient electrocatalytic performance in the oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), carbon dioxide reduction reaction (CRR), supercapacitors, tandem electrocatalysis and so on. The research challenges and problems of SURMOFs for electrocatalytic applications are also discussed at the end of the review.

Computation of Electromagnetic Properties of Molecular Ensembles

We outline a methodology for efficiently computing the electromagnetic response of molecular ensembles. The methodology is based on the link that we establish between quantum‐chemical simulations and the transfer matrix (T‐matrix) approach, a common tool in physics and engineering. We exemplify and analyze the accuracy of the methodology by using the time‐dependent Hartree‐Fock theory simulation data of a single chiral molecule to compute the T‐matrix of a cross‐like arrangement of four copies of the molecule, and then computing the circular dichroism of the cross. The results are in very good agreement with full quantum‐mechanical calculations on the cross. Importantly, the choice of computing circular dichroism is arbitrary: Any kind of electromagnetic response of an object can be computed from its T‐matrix. We also show, by means of another example, how the methodology can be used to predict experimental measurements on a molecular material of macroscopic dimensions. This is possible because, once the T‐matrices of the individual components of an ensemble are known, the electromagnetic response of the ensemble can be efficiently computed. This holds for arbitrary arrangements of a large number of molecules, as well as for periodic or aperiodic molecular arrays. We identify areas of research for further improving the accuracy of the method, as well as new fundamental and technological research avenues based on the use of the T‐matrices of molecules and molecular ensembles for quantifying their degrees of symmetry breaking. We provide T‐matrix‐based formulas for computing traditional chiro‐optical properties like (oriented) circular dichroism, and also for quantifying electromagnetic duality and electromagnetic chirality. The formulas are valid for light‐matter interactions of arbitrarily‐high multipolar orders.

Thin Films of Homochiral Metal–Organic Frameworks for Chiroptical Spectroscopy and Enantiomer Separation

Chiral nanoporous solids are a fascinating class of materials, allowing efficient enantiomer separation. Here, we review the status, applications, and potential of thin films of homochiral metal–organic frameworks (MOFs). Combining the advantages of MOFs, whose well-defined, crystalline structures can be rationally tuned, with the benefits of thin films enables new opportunities for the characterization of the enantioselectivity, e.g., via chiroptical spectroscopy and straightforward molecular uptake quantifications. By incorporating photoresponsive molecules in the chiral MOF films, the enantioselectivity of the material can be dynamically remote-controlled. The most promising application of MOF films is their use as membranes, where the enantioselective separation of chiral molecules is demonstrated and parameters for further improvements are discussed.

Facile Orientational Control of M2L2P SURMOFs on ⟨100⟩ Silicon Substrates and Growth Mechanism Insights for Defective MOFs

Layer-by-layer growth of Cu₂(bdc)₂(dabco) surface-mounted metal-organic frameworks (SURMOFs) was investigated on silicon wafers treated with different surface anchoring molecules. Well-oriented growth along the [100] and [001] directions could be achieved with simple protocols: growth along the [100] direction was achieved by substrate pretreatment with 80 °C piranha, while growth along the [001] direction was enabled by only rinsing silicon with absolute ethanol. Growth along the [001] direction produced more homogeneous SURMOF films. Optimization to enhance [001]-preferred orientation growth revealed that small changes in the SURMOF growth sequence (the number of rinse steps and linker concentrations) have a noticeable impact on the final film quality and the number of misaligned crystals. This new straightforward protocol was used to successfully grow other layer pillar-type SURMOFs, including the growth of Cu₂(bdc)₂(bipy) with simultaneous suppression of framework interpenetration.

Liquid-Phase Epitaxial Growth of Azapyrene-Based Chiral Metal-Organic Framework Thin Films for Circularly Polarized Luminescence

Development of chiral metal-organic frameworks (MOFs) for circularly polarized luminescence (CPL) is a challenging but important task. In this work, we report a first example of azapyrene-based chiral MOF thin films [Zn₂Cam₂DAP]_n grown on functionalized substrates (named SURchirMOF-4) for CPL property. By using a liquid-phase epitaxial layer-by-layer method, the resulted SURchirMOF-4 was constructed from chiral camphoric acid and 2,7-diazapyrene ligand, which has high orientation and homogeneity. The circular dichroism, CPL, and enantioselective adsorption results show that SURchirMOF-4 has strong chirality and CPL property as well as good enantioselective adsorption toward enantiomers of methyl-lactate. The synthesis of azapyrene-based chiral MOF thin films not only represents an ideal model for studying the enantioselective adsorption, but also will be a valuable approach for development of the chiral thin film exhibiting CPL property.

Switching the enantioselectivity of nanoporous host materials by light

A chiral photoswitchable nanoporous material with remote-controllable enantioselective adsorption capacity is presented.

Oriented UiO-66 thin films through solution shearing

Here, we discuss the fabrication of oriented films of UiO-66 crystals via the solution shearing based deposition of the crystal suspension over functionalized silicon substrates.

Helical carbon tubes derived from epitaxial Cu-MOF coating on textile for enhanced supercapacitor performance

A new helical carbon tube material has been prepared from epitaxial Cu-MOF coating on textile by calcination treatment.

Review for chiral-at-metal complexes and metal-organic framework enantiomorphs

This review discusses chiral-at-metal complexes and introduces enantiomorphs from assembly structure. Owing to the diverse coordination number and activity of metal ions as chiral centers, abundant structures for chiral selectivity, catalysis, and polarized light-response are the notable advantages of the chiral-at-metal complexes. The rational design and preparation of linear multi-dentate ligands is a good choice to improve the stability of chiral complexes, such as multi-bonding structure for high stability as a self-limiting system. The bio-significance and potential application of chiral-at-metal complexes are discussed, such as the synergistic effect of catalysis and chiral selectivity of the metal center in enzymes. Enzyme could be remolded to replace the original central metal ions with highly active rare earth or precious metal ions to form artificial metalloenzyme or to remove the "redundant" part around the metal center to improve the accessibility of substrate. The polarized light-response mechanism of chiral opsin is introduced in relation to its role in animal migration. Metal-organic frameworks (MOFs) are crystalline and porous materials built from metal nodes or clusters and organic linkers and provide the possibility to prepare artificial enantiomorphs. The preparations, applications, and characterization methods of MOF enatiomorphs are therefore introduced. We hope this review inspires researchers at all levels of their career to consider the title topic in their own research in terms of its application and potential value.

Surface-mounted MOF templated fabrication of homochiral polymer thin film for enantioselective adsorption of drugs

A chiral porous polymer thin film has been prepared using a template of SURMOF, showing an enantioselective adsorption of naproxen.

A Confined Fabrication of Perovskite Quantum Dots in Oriented MOF Thin Film

Organic-inorganic hybrid lead organohalide perovskites are inexpensive materials for high-efficiency photovoltaic solar cells, optical properties, and superior electrical conductivity. However, the fabrication of their quantum dots (QDs) with uniform ultrasmall particles is still a challenge. Here we use oriented microporous metal-organic framework (MOF) thin film prepared by liquid phase epitaxy approach as a template for CH₃NH₃PbI₂X (X = Cl, Br, and I) perovskite QDs fabrication. By introducing the PbI₂ and CH₃NH₃X (MAX) precursors into MOF HKUST-1 (Cu₃(BTC)₂, BTC = 1,3,5-benzene tricarboxylate) thin film in a stepwise approach, the resulting perovskite MAPbI₂X (X = Cl, Br, and I) QDs with uniform diameters of 1.5-2 nm match the pore size of HKUST-1. Furthermore, the photoluminescent properties and stability in the moist air of the perovskite QDs loaded HKUST-1 thin film were studied. This confined fabrication strategy demonstrates that the perovskite QDs loaded MOF thin film will be insensitive to air exposure and offers a novel means of confining the uniform size of the similar perovskite QDs according to the oriented porous MOF materials.

Chiral Chemistry of Homochiral Porous Thin Film with Different Growth Orientations

Chirality is one of the essential features in our living life and exerts a wide variety of applications in enantio-adsorption/separation. However, the mechanism between chirality and enantio-adsorption/separation is very significant in homochiral porous materials; in particular, the understanding of the relationship between crystalline orientations and chiral behavior is a challenging but important mechanism. In this work, homochiral porous crystalline metal organic framework (MOF) materials were grown on hydroxyl- and carboxyl-functionalized substrates, resulting in homochiral porous thin films with different orientations. The enantioselectivity and adsorption rates in two different oriented homochiral porous thin films were studied by using gas-phase quartz crystal microbalance (QCM) experiment of chiral probe molecules. The different mass uptake and time constant showed that the chiral behavior can be obviously influenced by the crystalline orientations on the same homochiral porous thin films. This study will not only offer a good model to understand the mechanism of chiral behavior in homochiral porous materials but also provide guidance for developing new homochiral-oriented porous thin films with high enantioselectivity or enantioseparation.

Chiral chemistry of metal-camphorate frameworks

This critical review presents the various synthetic approaches and chiral chemistry of metal-camphorate frameworks (MCamFs), which are homochiral metal-organic frameworks (MOFs) constructed from a camphorate ligand. The interest in this unique subset of homochiral MOFs is derived from the many interesting chiral features for both materials and life sciences, such as asymmetrical synthesis or crystallization, homochiral structural design, chiral induction, absolute helical control and ligand handedness. Additionally, we discuss the potential applications of homochiral MCamFs. This review will be of interest to researchers attempting to design other homochiral MOFs and those engaged in the extension of MOFs for applications such as chiral recognition, enantiomer separation, asymmetric catalysis, nonlinear sensors and devices.

Enantioselective adsorption in homochiral metal-organic frameworks: the pore size influence

Uptake experiments in thin films of isoreticular chiral MOFs of type Cu2(Dcam)2(L) with identical stereogenic centers but different pore dimensions show that the enantioselectivity is significantly influenced by the pore size. The highest selectivity was found for medium pore sizes, roughly corresponding to the extension of the chiral guest molecule, limonene.

Chiral Porous Metacrystals: Employing Liquid-Phase Epitaxy to Assemble Enantiopure Metal-Organic Nanoclusters into Molecular Framework Pores

We describe the fabrication of hybrid yet well-ordered porous nanoparticle (NP) arrays with full three-dimensional periodicity by embedding nanometer-sized metal-organic clusters (MOCs) into metal-organic frameworks (MOFs). Although conventional NP@MOF encapsulation procedures failed for these fairly large (1.66 nm diameter) NPs, we achieved maximum loading efficiency (one NP per pore) by using a modified liquid phase epitaxy (LPE) layer-by-layer approach to grow and load the MOF. The preformed NPs, homochiral Ti4(OH)4(R/S-BINOL)6 clusters (Ti-MOC, BINOL = 1,1'-bi-2-naphthol), formed a regular lattice inside the pores of an achiral HKUST-1 (or Cu3(BTC)2, BTC = 1,3,5-benzenetricarboxylate) MOF thin film. Exposure to the different enantiomers of methyl lactate revealed that the NP@MOF metacrystal is quite efficient regarding enantiomer recognition and separation. The approach presented here is also suited for other MOF types and expected to provide a substantial stimulus for the fabrication of metacrystals, crystalline solids made from nanoparticles instead of atoms.

Liquid-Phase Epitaxy Effective Encapsulation of Lanthanide Coordination Compounds into MOF Film with Homogeneous and Tunable White-Light Emission

As a new family of hybrid inorganic-organic materials with large porosity, metal-organic frameworks (MOFs) have received attractive attention recently on encapsulating functional guest species. Although the encapsulation of luminescent guest into bulk MOFs can tune the luminescent property, the powder composite materials are limited to the application in optical sensors and devices. In the present work, we use a modified liquid-phase epitaxial (LPE) pump method for the fabrication of lanthanide coordination compounds (LCCs)-encapsulated MOF thin film on substrate with high encapsulation efficiency. The resultant composite film reveals an oriented and homogeneous composite film, in which a white light emission by tuning the LCCs of red, blue and green emission can be obtained. This strategy may open new perspectives for developing high-encapsulation-efficiency, oriented, and homogeneous solid-state lighting composite films in the application of optical sensors and devices.

Planar-chiral building blocks for metal–organic frameworks

The first example of a planar-chiral building block being used for chiral metal–organic frameworks (MOFs) is presented.