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Purification of C2H4 from the ternary C2 hydrocarbon mixture in one step is of critical significance but still extremely challenging according to its intermediate physical properties between C2H6 and C2H2. Hydrogen-bonded organic frameworks (HOFs) stabilized by supramolecular interactions are emerging as a new kind of adsorbents that facilitate green separation. However, it remains a problem to efficiently realize the one-step C2H4 purification from C2H6/C2H4/C2H2 mixture because of the low C2H2/C2H4 selectivity. We herein report a robust microporous HOF (termed as HOF-TDCPB) with dense O atoms and aromatic rings distributed on the pore surface which provide C2H6 and C2H2 preferred environment simultaneously. Dynamic breakthrough experiments indicate that HOF-TDCPB can not only obtain high-purity C2H4 from binary C2 mixture, but also firstly realize one-step C2H4 purification from ternary C2H6/C2H4/C2H2 mixture, with the C2H4 productivity of 3.2 L/kg (>99.999%) for one breakthrough cycle. Furthermore, HOF-TDCPB displays outstanding stability in air, organic solvents and water, which endow it excellent cycle performance even under high-humidity conditions. Theoretical calculations indicate that multiple O sites on pore channels can create synergistic binding sites for C2H2, thus affording overall stronger multipoint interactions., (© 2024 Wiley‐VCH GmbH.)

Efficient capture and storage of radioactive I 2 is a prerequisite for developing nuclear power but remains a challenge. Here, two flexible Ag-MOFs (FJI-H39 and 40) with similar active sites but different pore sizes and flexibility are prepared; both of them can capture I 2 with excellent removal efficiencies and high adsorption capacities. Due to the more flexible pores, FJI-H39 not only possesses the record-high I 2 storage density among all the reported MOFs but also displays a very fast adsorption kinetic (124 times faster than FJI-H40), while their desorption kinetics are comparable. Mechanistic studies show that FJI-H39 can undergo induced-fit transformations continuously (first contraction then expansion), making the adsorbed iodine species enrich near the Ag(I) nodes quickly and orderly, from discrete I - anion to the dense packing of various iodine species, achieving the very fast adsorption kinetic and the record-high storage density simultaneously. However, no significant structural transformations caused by the adsorbed iodine are observed in FJI-H40. In addition, FJI-H39 has excellent stability/recyclability/obtainability, making it a practical adsorbent for radioactive I 2 . This work provides a useful method for synthesizing practical radioactive I 2 adsorbents., (© 2024 Wiley‐VCH GmbH.)

n-C 4 H 10 and iso-C 4 H 10 are both important petrochemical raw materials. Considering the coexistence of the isomers in the production process, it is necessary to achieve their efficient separation through an economical way. However, to obtain high-purity n-C 4 H 10 and iso-C 4 H 10 in one-step separation process, developing iso-C 4 H 10 -exclusion adsorbents with high n-C 4 H 10 adsorption capacity is crucial. Herein, we report a cage-like MOF (SIFSIX-Cu-TPA) with small windows and large cavities which can selectively allow smaller n-C 4 H 10 enter the pore and accommodate a large amount of n-C 4 H 10 simultaneously. Adsorption isotherms reveal that SIFSIX-Cu-TPA not only completely excludes iso-C 4 H 10 in a wide temperature range, but also exhibits a very high n-C 4 H 10 adsorption capacity of 94.2 cm 3  g -1 at 100 kPa and 298 K, which is the highest value among iso-C 4 H 10 -exclusion-type adsorbents. Breakthrough experiments show that SIFSIX-Cu-TPA has excellent n/iso-C 4 H 10 separation performance and can achieve a record-high productivity of iso-C 4 H 10 (3.2 mol kg -1 ) with high purity (>99.95 %) as well as 3.0 mol kg -1 of n-C 4 H 10 (>99 %) in one separation circle. More importantly, SIFSIX-Cu-TPA can realize the efficient separation of butanes at different flow rates, temperatures, as well as under high humid condition, which indicates that SIFSIX-Cu-TPA can be deemed as an ideal platform for industrial butane isomers separation., (© 2024 Wiley-VCH GmbH.)

The one-step efficient separation of high-purity C 2 H 4 from C 2 H 4 /C 2 H 6 mixtures by hydrogen-bonded organic frameworks (HOFs) faces two problems: lack of strategies for constructing stable pores in HOFs and how to obtain high C 2 H 6 selectivity. Herein, we have developed a microporous Mortise-Tenon-type HOF (MTHOF-1, MT is short for Mortise-Tenon structure) with a new self-assembly mode for C 2 H 4 /C 2 H 6 separation. Unlike previous HOFs which usually possess discrete head-to-head hydrogen bonds, MTHOF-1 is assembled by unique consecutive side-by-side hydrogen bonds, which result in mortise-and-tenon pores decorated with orderly arranged amide groups and benzene rings. As expected, MTHOF-1 exhibits excellent stability under various conditions and shows clear separation trends for C 2 H 6 /C 2 H 4 . The IAST selectivity is as high as 2.15 at 298 K. More importantly, dynamic breakthrough experiments have demonstrated that MTHOF-1 can effectively separate the C 2 H 6 /C 2 H 4 feed gas to obtain polymer-grade C 2 H 4 in one step even under high-humidity conditions., (© 2024 Wiley‐VCH GmbH.)

Atherosclerosis (AS) is a crucial contributor to various cardiovascular diseases (CVDs), which seriously threaten human life and health. Early and accurate recognition of AS plaques is essential for the prevention and treatment of CVD. Herein, we introduce an AS-targeting nanoprobe based on near-infrared (NIR) persistent luminescence nanoparticles (PLNPs), developing a highly sensitive NIR persistent luminescence (PersL) AS plaque imaging technique and successfully realizing early AS plaque detection. The nanoprobe exhibits good monodispersity and regular spherical morphology and also owns exceptional NIR PersL performance upon repetitive irradiation by biological window light. The surface-conjugated antibody (anti-osteopontin) endowed nanoprobe excellent targeting ability to foam cells within plaques. After intravenously injected nanoprobe into AS model mice, the highly sensitive PersL imaging technique can accurately detect AS plaques prior to ultrasonography (US) and magnetic resonance imaging (MRI). Specifically, the NIR PersL imaging reveals AS plaques at the earliest within 2 weeks, with higher signal-to-background ratio (SBR) up to 5.72. Based on this technique, the nanoprobe has great potential for applications in the prevention and treatment of CVD, the study of AS pathogenesis, and the screening of anti-AS drugs.

Inherent "soft" ionic lattice nature of halide perovskite quantum dots (QDs), triggered by the weak Pb-X (X=Cl, Br, I) bond, is recognized as the primary culprit for their serious instability. A promising way is to construct exceedingly strong ionic interaction inside the QDs and increase their crystal cohesive energy by substituting the interior X - with highly electronegative F - , however, which is challenging and hitherto remains unreported. Here, a "whole-body" fluorination strategy is proposed for strengthening the interior bonding architecture of QDs, wherein the F - are uniformly distributed throughout the whole nanocrystal encompassing both the interior lattice and surface, successfully stabilizing their "soft" crystal lattice and passivating surface defects. This approach effectively mitigates their intrinsic instability issues including light-induced phase segregation. As a result, light-emitting devices based on these QDs exhibit exceptional efficiency and remarkable stability., (© 2024 Wiley-VCH GmbH.)

H 2 O 2 is a widely used eco-friendly oxidant and a potential energy carrier. Photocatalytic H 2 O 2 production from water and O 2 is an ideal approach with the potential to address the current energy crisis and environmental issues. Three zig-zag two-dimensional coordination polymers (2D CPs), named CuX-dptz, were synthesized by a rapid and facile method at room temperature, showing preeminent H 2 O 2 photoproduction performance under pure water and open air without any additives. CuBr-dptz exhibits a H 2 O 2 production rate high up to 1874 μmol g -1  h -1 , exceeding most reported photocatalysts under this condition, even comparable to those supported by sacrificial agents and O 2 . The coordination environment of Cu can be modulated by halogen atoms (X=Cl, Br, I), which in turn affects the electron transfer process and finally determines the reaction activity. This is the first time that 2D CPs have been used for photocatalytic H 2 O 2 production in such challenging conditions, which provides a new pathway for the development of portable in situ H 2 O 2 photosynthesis devices., (© 2023 Wiley-VCH GmbH.)

Metal-organic frameworks (MOFs) are considered to be a promising porous material due to their excellent porosity and chemical tailorability. However, due to the relatively weak strength of coordination bonds, the stability ( e.g. , water stability) of MOFs is usually poor, which severely inhibits their practical applications. To prepare water-stable MOFs, several important strategies such as increasing the bonding strength of building units and introducing hydrophobic units have been proposed, and many MOFs with excellent water stability have been prepared. Carbon dioxide not only causes a range of climate and health problems but also is a by-product of some important chemicals ( e.g. , natural gas). Due to their excellent adsorption performances, MOFs are considered as a promising adsorbent that can capture carbon dioxide efficiently and energetically, and many water-stable MOFs have been used to capture carbon dioxide in various scenarios, including flue gas decarbonization, direct air capture, and purified crude natural gas. In this review, we first introduce the design and synthesis of water-stable MOFs and then describe their applications in carbon dioxide capture, and finally provide some personal comments on the challenges facing these areas., Competing Interests: The authors declare no conflicts of interest., (This journal is © The Royal Society of Chemistry.)

Mandelic acid and its analogues are highly valuable medical intermediates and play an important role in the pharmaceutical industry, biochemistry, and life sciences. Therefore, effective enantioselective recognition and separation of mandelic acid are of great significance. In this study, two of our recently reported chiral amine-alcohol-functionalized UiO-68-type Zr-HMOFs 1 and 3 with high chemical stability, abundant binding sites, and large chiral pores were selected as chiral selectors for the enantioselective separation of mandelic acid (MA), methyl mandelate (MM), and other chiral molecules containing only one phenyl. Materials 1 and 3 exhibited excellent enantioselective separation performance for MA and MM. Especially for the separation of racemate MA, the enantiomeric excess values reached 97.3 and 98.9%, which are the highest reported values so far. Experimental and density functional theory (DFT) computational results demonstrated that the introduction of additional phenyls on the chiral amine alcohol pendants in 3 had somewhat impact on the enantioselective adsorption and separation of MA or MM compared with 1 , but it was not significant. Further research on the enantioselective separation of those chiral adsorbates containing only one phenyl by material 1 indicated the crucial role of the groups directly bonded to the chiral carbons of the adsorbates in the selective separation of enantiomers, especially showing higher enantioselectivity for the adsorbates with two hydrogen-bonding groups directly bonded to its chiral carbon.

Traditional nonlinear optical (NLO) crystals are exclusively limited to ionic crystals with π-conjugated groups and it is a great challenge to achieve a subtle balance between second-harmonic generation, bandgap, and birefringence for them, especially in the deep-UV spectrum region (E g  > 6.20 eV). Herein, a non-π-conjugated molecular crystal, NH 3 BH 3 , which realizes such balance with a large second-harmonic generation response (2.0 × KH 2 PO 4 at 1064 nm, and 0.45 × β-BaB 2 O 4 at 532 nm), deep-UV transparency (E g > 6.53 eV), and moderate birefringence (Δn = 0.056@550 nm) is reported. As a result, NH 3 BH 3 exhibits a large quality factor of 0.32, which is evidently larger than those of non-π-conjugated sulfate and phosphate ionic crystals. Using an unpolished NH 3 BH 3 crystal, effective second-harmonic generation outputs are observed at different wavelengths. These attributes indicate that NH 3 BH 3 is a promising candidate for deep-UV NLO applications. This work opens up a new door for developing high-performance deep-UV NLO crystals., (© 2023 Wiley-VCH GmbH.)

Excessive CO 2 in the air can not only lead to serious climate problems but also cause serious damage to humans in confined spaces. Here, a novel metal-organic framework (FJI-H38) with adaptive ultramicropores and multiple active sites is prepared. It can sieve CO 2 from air with the very high adsorption capacity/selectivity but the lowest adsorption enthalpy among the reported physical adsorbents. Such excellent adsorption performances can be retained even at high humidity. Mechanistic studies show that the polar ultramicropore is very suitable for molecular sieving of CO 2 from N 2 , and the distinguishable adsorption sites for H 2 O and CO 2 enable them to be co-adsorbed. Notably, the adsorbed-CO 2 -driven pore shrinkage can further promote CO 2 capture while the adsorbed-H 2 O-induced phase transitions in turn inhibit H 2 O adsorption. Moreover, FJI-H38 has excellent stability and recyclability and can be synthesized on a large scale, making it a practical trace CO 2 adsorbent. This will provide a new strategy for developing practical adsorbents for CO 2 capture from the air., (© 2023 Wiley-VCH GmbH.)

Crystal-field perturbation is theoretically the most direct and effective method of achieving highly efficient photoluminescence from trivalent lanthanide (Ln 3+ ) ions through breaking the parity-forbidden nature of their 4f-transitions. However, exerting such crystal-field perturbation remains an arduous task even in well-developed Ln 3+ -doped luminescent nanocrystals (NCs). Herein, we report crystal-field perturbation through interstitial H + -doping in orthorhombic-phase NaMgF 3 :Ln 3+ NCs and achieve a three-orders-of-magnitude emission amplification without a distinct lattice distortion. Mechanistic studies reveal that the interstitial H + ions perturb the local charge density distribution, leading to anisotropic polarization of the F - ligand, which affects the highly symmetric Ln 3+ -substituted [MgF 6 ] 4- octahedral clusters. This effectively alleviates the parity-forbidden selective rule to enhance the 4f-4 f radiative transition rate of the Ln 3+ emitter and is directly corroborated by the apparent shortening of the radiative recombination lifetime. The interstitially H + -doped NaMgF 3 :Yb/Er NCs are successfully used as bioimaging agents for real-time vascular imaging. These findings provide concrete evidence for crystal-field perturbation effects and promote the design of Ln 3+ -doped luminescent NCs with high brightness., (© 2023. Springer Nature Limited.)

Near-infrared (NIR) fluorescence imaging poses significant superiority over traditional medical imaging for tumor resection, thus having attracted widely attention. However, for tiny tumor residues, it requires relative high sensitivity to determine. Here, based on persistent luminescence nanoparticles (PLNPs), an ultrasensitive nanoprobe with extraordinary tumor imaging result is developed to guide surgical removal. Persistent luminescence (PersL) is quenched in normal tissue by the outer layer of MnO 2 , and is recovered due to the degradation of MnO 2 in tumor microenvironment, significantly improving the sensitivity of tumor imaging. Combined with the absence of background fluorescence in imaging of PLNPs, ultrahigh sensitivity is achieved. In orthotopic breast cancer model, the intraoperative tumor-to-normal tissue (T/NT) signal ratio of the nanoprobe is 58.8, about 9 times that of downconversion nanoparticles. The T/NT ratio of residual tumor (<2 mm) remains 12.4, considerably high to distinguish tumor tissue from normal tissue. Besides, multiple-microtumor, 4T1 liver-implanted tumor and lung metastasis models are built to prove that this ultrasensitive nanoprobe is feasible to recognize tumor residues. Notably, PersL imaging takes only 1.5 min, appropriate to be applied for intraoperative imaging. Overall, an ultrasensitive and convenient imaging for recognizing residual tumor tissue is introduced, holding promise for complete surgical removal., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Homochiral metal-organic frameworks (HMOFs) have been widely investigated in the application of enantiomeric separation. Nonetheless, it remains a significant challenge to explore the effect of multiple weak interactions between HMOF adsorbents and chiral adsorbates on enantiomeric separation performance still. In this work, robust chiral amine-alcohol-functionalized UiO-68-typed Zr-HMOFs 1 - 3 with the same hydrogen-bonding sites but slightly different π-binding sites were prepared for the enantioseparation of amino acid derivatives (Fmoc-AAs) with large π-binding groups. As a consequence of multiple host-guest interactions, these Zr-HMOFs exhibit speedy adsorption and high adsorption capacity for Fmoc- L / D -AAs and dissimilar enantioselectivity for the adsorption of their enantiomers. Materials 1 and 2 exhibit excellent enantioselective separation performance for Fmoc-valine with a single terminal π-binding group, while material 3 displays excellent enantioselective separation performance for Fmoc-phenylalanine and Fmoc-tryptophan with π-binding groups at both ends. As evidently demonstrated by our experimental and density functional theory (DFT) computational results, when the number of π-binding groups preset in the confined chiral space of adsorbents matches the number of π-binding groups of chiral adsorbates, the synergism of π-π or σ-π interactions will increase enantioselectivity; otherwise, the competition interactions from redundant identical binding sites will weaken enantioselectivity. Our case not only provides a tremendously typical system for investigating the collaborative discrimination of multiple weak interactions and exploring the impact of relatively excessive binding sites of HMOF adsorbents or chiral adsorbates on the enantioselective separation performance but also provides guidance for targeted functional modifications of high-performance chiral porous materials.

Exciton localization is an approach for preparing highly luminescent semiconductors. However, realizing strongly localized excitonic recombination in low-dimensional materials such as two-dimensional (2D) perovskites remains challenging. Herein, we first propose a simple and efficient Sn 2+ vacancy (V Sn ) tuning strategy to enhance excitonic localization in 2D (OA) 2 SnI 4 (OA=octylammonium) perovskite nanosheets (PNSs), increasing their photoluminescence quantum yield (PLQY) to ≈64 %, which is among the highest values reported for tin iodide perovskites. Combining experimental with first-principles calculation results, we confirm that the significantly increased PLQY of (OA) 2 SnI 4 PNSs is primarily due to self-trapped excitons with highly localized energy states induced by V Sn . Moreover, this universal strategy can be applied for improving other 2D Sn-based perovskites, thereby paving a new way to fabricate diverse 2D lead-free perovskites with desirable PL properties., (© 2023 Wiley-VCH GmbH.)

Organic-inorganic hybrid perovskites carry unique semiconducting properties and advanced flexible crystal structures. These characteristics of organic-inorganic hybrid perovskites create a promising candidacy for circularly polarized light (CPL) detection. However, CPL detections based on chiral perovskites are limited to UV and visible wavelengths. The natural quantum well structures of layered hybrid perovskites generate strong light-matter interactions. This makes it possible to achieve near-infrared (NIR) CPL detection via two-photon absorption in the sub-wavelength region. In this study, cooperative strategies of dimension increase and mixed spacer cations are used to obtain a pair of chiral multilayered perovskites (R-β-MPA)EA 2 Pb 2 Br 7 and (S-β-MPA)EA 2 Pb 2 Br 7 (MPA = methylphenethylammonium and EA = ethylammonium). The distinctive bi-cations interlayer and multilayered inorganic skeletons provide enhanced photoconduction. Moreover, superior photoconduction leads to the prominent NIR CPL response with a responsivity up to 8.1 × 10 -5 A W -1 . It is anticipated that this work can serve as a benchmark for the fabrication and optimization of efficient NIR CPL detection by simple chemical design., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Developing practical storage technologies for acetylene (C 2 H 2 ) is important but challenging because C 2 H 2 is useful but explosive. Here, a novel metal-organic framework (MOF) (FJI-H36) with adaptive channels was prepared. It can effectively capture C 2 H 2 (159.9 cm 3  cm -3 ) at 1 atm and 298 K, possessing a record-high storage density (561 g L -1 ) but a very low adsorption enthalpy (28 kJ mol -1 ) among all the reported MOFs. Structural analyses show that such excellent adsorption performance comes from the synergism of active sites, flexible framework, and matched pores; where the adsorbed-C 2 H 2 can drive FJI-H36 to undergo induced-fit transformations step by step, including deformation/reconstruction of channels, contraction of pores, and transformation of active sites, finally leading to dense packing of C 2 H 2 . Moreover, FJI-H36 has excellent chemical stability and recyclability, and can be prepared on a large scale, enabling it as a practical adsorbent for C 2 H 2 . This will provide a useful strategy for developing practical and efficient adsorbents for C 2 H 2 storage., (© 2022 Wiley-VCH GmbH.)

Benefiting from superior semiconducting properties and the angle-dependence of the bulk photovoltaic effect (BPVE) on polarized light, the two-dimensional (2D) hybrid perovskite ferroelectrics are developed for sensitive self-powered polarized photodetection. Most of the currently reported ferroelectric-driven polarized photodetection is restricted to the shortwave optical response, and expanding the response range is urgently needed. Here we report the first instance of a FAPbI 3 -derived (2D) perovskite ferroelectric, (BA) 2 (FA)Pb 2 I 7 ( 1 , BA is n -butylammonium, FA is formamidinium). It exhibited a notably high thermostability and broad-spectrum adsorption extending to around 650 nm. Significantly, 1 demonstrated ferroelectricity-driven self-powered polarized photodetection under 637 nm with an anisotropic photocurrent ratio of ∼1.96, ultrahigh detectivity of 3.34 × 10 12 Jones, and long-term repetition. This research will shed light on the development of new ferroelectrics for potential application in broad-spectrum polarization-based optoelectronics.

Competing Interests: Conflict of interest The authors declare that they have no conflict of interest.

Porous supramolecular assemblies constructed by noncovalent interactions are promising for adsorptive purification of methane because of their easy regeneration. However, the poor stability arising from the weak noncovalent interactions has obstructed their practical applications. Here, we report a robust and easily regenerated polyhedron-based cationic framework assembled from a metal-organic square. This material exhibits a very low affinity for CH 4 and N 2 , but captures other competing gases (e.g. C 2 H 6 , C 3 H 8 , and CO 2 ) with a moderate affinity. These results underpin highly selective separation of a range of gas mixtures that are relevant to natural gas and industrial off-gas. Dynamic breakthrough studies demonstrate its practical separation for C 2 H 6 /CH 4 , C 3 H 8 /CH 4 , CO 2 /N 2 , and CO 2 /CH 4 . Particularly, the separation time is ≈11 min g -1 for the C 2 H 6 /CH 4 (15/85 v/v) mixture and ≈49 min g -1 for the C 3 H 8 /CH 4 (15/85 v/v) mixture (under a flow of 2.0 mL min -1 ), respectively, enabling its capability for CH 4 purification from light alkanes., (© 2022 Wiley-VCH GmbH.)

Considering the importance of C 2 H 2 in industry, it is of great significance to develop porous materials for efficient C 2 H 2 /CO 2 separation. Besides the high selectivity, the C 2 H 2 adsorption capacity is another vital factor in C 2 H 2 /CO 2 separation. However, the "trade-off" between these two factors is still perplexing. Rational pore design of metal-organic frameworks (MOFs) has been proven to be an effective way to solve the above problem. In this work, we have appropriately combined three kinds of strategies in the design of the MOF ( FJI-H33 ), i.e., the introduction of open metal sites, construction of cage-like cavities, and adjustment of moderate pore size. As anticipated, FJI-H33 exhibits both outstanding C 2 H 2 adsorption capacity and high C 2 H 2 /CO 2 selectivity. At 298 K and 100 kPa, the C 2 H 2 storage capacity of FJI-H33 is 154 cm 3 /g, while the CO 2 uptake is only 80 cm 3 /g. The ideal adsorbed solution theory (IAST) selectivity of C 2 H 2 /CO 2 (50:50) is calculated as high as 15.5 at 298 K. More importantly, the excellent practical separation performance was verified by breakthrough experiments. In addition, the calculation of adsorption sites and relevant energy by density functional theory (DFT) provides a good explanation for the excellent separation performance and pore design strategy.

Antiperovskites have been studied since the 1980s because of their rich physical and chemical properties, but their linear and second-order nonlinear optical responses remain largely unknown. Here we report a new polar crystal, Cs 3 Cl(HC 3 N 3 S 3 ) (I), which features a quasi-one-dimensional antiperovskite structure composed of ClCs 6 polyhedra and A-site [HC 3 N 3 S 3 ] 2- rings. To our best knowledge, this kind of antiperovskite structure is reported for the first time. Remarkably, I exhibits a very strong nonlinear optical response up to 11.4 times that of the benchmark KH 2 PO 4 and exceptionally large birefringence of 0.52. The first-principles calculations and structural analyses reveal that [HC 3 N 3 S 3 ] 2- is the "material gene" while the antiperovskite structural feature making it in a favorable arrangement. This work provides a new structural platform for the rational design of integrated optoelectronic materials with linear and second-order nonlinear optical responses., (© 2022 Wiley-VCH GmbH.)

Because C 2 H 4 plays an essential role in the chemical industry, economical and energy-efficient separation of ethylene (C 2 H 4 ) from ethane (C 2 H 6 ) is extremely important. With the exception of energy-intensive cryogenic distillation, there are few one-step methods to obtain polymer-grade (≥99.95 % pure) C 2 H 4 from C 2 H 4 /C 2 H 6 mixtures. Here we report a highly stable metal-organic-framework (MOF) FJI-H11-Me(des) (FJI-H=Hong's group in Fujian Institute of Research on the Structure of Matter) which features one-dimensional hexagonal nonpolar pore surfaces constructed by aromatic rings and alkyl groups. This FJI-H11-Me(des) adsorbs C 2 H 6 rather than C 2 H 4 between 273 and 303 K. Practical breakthrough experiments with C 2 H 4 containing 1 % C 2 H 6 have shown that FJI-H11-Me(des) can realize the acquisition in one-step of polymer-grade, 99.95 % pure C 2 H 4 under various conditions including different gas flow rates, temperatures and relative humidity., (© 2022 Wiley-VCH GmbH.)

Luminescence stability is a critical consideration for applying phosphors in practical devices. In this work, we report two categories of double p-tert -butylthiacalix[4]arene (H 4 TC4A) capped clusters that exhibit characteristic lanthanide luminescence. Specifically, {[Ln 4 (μ 4 -OH)(TC4A) 2 (DMF) 6 (CH 3 OH) 3 (HCOO)Cl 2 ]}· x CH 3 OH (Ln = Eu (1), Tb (2); x = 0-1) with square-planar [Ln 4 (μ 4 -OH)] cluster cores and {[Ln 9 (μ 5 -OH) 2 (μ 3 -OH) 8 (OCH 3 ) (TC4A) 2 (H 2 O) 24 Cl 9 ]}· x DMF (Ln = Gd (3), Tb (4), Dy (5); x = 2-6) with hourglass-like [Ln 9 (μ 5 -OH) 2 (μ 3 -OH) 8 ] cluster cores are synthesized and characterized. By comparing 2 and 4, we find that several critical luminescence properties (such as quantum efficiency and luminescence stabilities) depend directly on the cluster core structure. With the square-planar [Ln 4 (μ 4 -OH)] cluster cores, 2 demonstrates high quantum yield (∼65%) and excellent luminescence stability against moisture, high temperature, and UV-radiation. A white light-emitting diode (LED) with ultrahigh color quality is successfully fabricated by mixing 2 with commercial phosphors. These results imply that high quality phosphors might be achieved by exploiting the double thiacalix[4]arene-capping strategy, with an emphasis on the cluster core structure., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Birefringent materials are highly demanded for high-performance polarized optics. As compared with artificial anisotropic metamaterials, anisotropic crystals have advantages of low optical losses and easy processing, but their birefringence is still limited. Herein, based on first-principles studies, we identified a new type of functional anion units, (H x C 6 N 9 ) (3-x)- (x=0, 1, 2), and then successfully synthesized a new anisotropic crystal, namely, CsH 2 C 6 N 9 ⋅H 2 O (I), whose crystal structure consists of (H 2 C 6 N 9 ) - anions. Remarkably, I is ultraviolet transparent and exhibits very large birefringence of about 0.55@550 nm, which is much larger than those of commercial birefringent crystals. These results make I a candidate for highly efficient manipulation of optics and light in optical modulation devices. Theoretical calculations reveal that large birefringence mainly arises from the cooperative π orbitals in (H 2 C 6 N 9 ) - anions. This work provides a new insight on the underlying structure-property relationships of anisotropic crystals., (© 2022 Wiley-VCH GmbH.)

Luminescent stability is a vital factor that dictates the application of lanthanide luminescent materials. Designing luminescent lanthanide cluster nodes that form an extended framework with predictable linking patterns may help enhance the structural stability of the lanthanide complexes and hence lead to improved luminescent stability. Herein, we report a series of one-dimensional (1D) rare-earth metal-organic framework compounds, {Ln 4 (μ 4 -OH)(TC4A) 2 (H 2 O) 2 (CH 3 O)(HCOO) 2 (HCOOH)}· x CH 3 OH (Ln = Sm ( 1 ), Eu ( 2 ), Tb ( 3 ), Dy ( 4 ); x = 1-5), based on double thiacalix[4]arene-capped Ln 4 (μ 4 -OH)(TC4A) 2 nodes. The axially capped Ln 4 (μ 4 -OH)(TC4A) 2 nodes are connected equatorially by formate bridges to form zigzag 1D-metal-organic framework (MOF) chains, which further assemble into a quasi-two-dimensional (2D) structure via hydrogen bonding. These unique features result in a stable structure and therefore superior luminescent stability. For example, the Tb-based 1D-MOF (3) exhibits intensive green photoluminescence with a quantum yield of 53% and an average decay time of 1.33 × 10 6 ns. It maintains its integrated emission intensity at 96.5, 94.5, and 89.4% of the original value after being exposed to moisture (soaking in water for 10 days), elevated temperature (150 °C), and UV (15 days of continuous radiation), respectively, demonstrating excellent luminescent stability. We adopt the Tb-based 1D-MOF ( 3 ) as the green phosphor and successfully fabricate a prototype white-light-emitting diode (LED) with stable emission under long-term operation. Our synthetic strategy allows control over the linking pattern of lanthanide nodes, providing a predictive route to obtain lanthanide MOFs with improved luminescent stability.

Controllable arrangement of different ligands in a single assembly will not only bring increased complexity but also offers a new route to fine-tune the function of the designed architecture. We report here a combinatorial self-assembly with enPd(NO 3 ) 2 and three different ligands (L 1-3 ), which gave rise to a family of six palladium-organic cages (C1-6) with systematically varied shapes and cavities, including three new heteroleptic (Pd 5 L 1 2 L 2 , Pd 5 L 1 2 L 3 , Pd 4 L 2 L 3 ), one new homoleptic (Pd 4 L 3 2 ) cages, and two known homoleptic (Pd 6 L 1 4 , Pd 4 L 2 2 ) cages. Emergent functions due to the fusion of two half cavities on the heteroleptic cages from their parent homoleptic cages have been observed: the heteroleptic cages can form ternary complexes by co-encapsulation of both aromatic and aliphatic guests, while their homoleptic counterparts can only form binary complexes. Such a forced co-encapsulation effect endows the heteroleptic cages with enhanced catalytic power for the Knoevenagel condensation., (© 2022 Wiley-VCH GmbH.)

Coordination hosts based on flexible ligands have received increasing attention due to their inherent adaptive cavities that often show induced-fit guest binding and catalysis like enzymes. Herein, we report the controlled self-assembly of a series of homo/heterometallic coordination hosts (Me 4 enPd) 2 n (ML) n [ n = 2/3; M = Zn(ii)/Co(ii)/Ni(ii)/Cu(ii)/Pd(ii)/Ag(i); Me 4 en: N , N , N ', N '-tetramethylethylenediamine] with different shapes (tube/cage) from a flexible tetraazacyclododecane-based pyridinyl ligand (L) and cis -blocking Me 4 enPd(ii) units. While the Ag(i)-metalated ligand (AgL) gave rise to the formation of a (Me 4 enPd) 4 (ML) 2 -type cage, all other M(ii) ions led to isostructural (Me 4 enPd) 6 (ML) 3 -type tubular complexes. Structural transformations between cages and tubes could be realized through transmetalation of the ligand. The buffering effect on the ML panels endows the coordination tubes with remarkable acid-base resistance, which makes the (Me 4 enPd) 6 (ZnL) 3 host an effective catalyst for the CO 2 to CO 3 2- conversion. Control experiments suggested that the integration of multiple active Zn(ii) sites on the tubular host and the perfect geometry match between CO 3 2- and the cavity synergistically promoted such a conversion. Our results provide an important strategy for the design of adaptive coordination hosts to achieve efficient carbon fixation., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Selective separation using porous adsorbents is an energy-efficient alternative to traditional separation techniques. Stacked porous organic molecular frameworks (POMFs) capable of noncovalent π⋅⋅⋅π interactions are emerging as a new kind of adsorbents that facilitate green separation. Here we report a robust porous molecular crystal (TAPM-1), which is stabilized by multiple intermolecular π⋅⋅⋅π interactions. With its long-range π-stacking, TAPM-1 has excellent hydrophobicity, thermostability, recyclability, and high selectivity for aromatics over the corresponding cyclic aliphatics. This enables TAPM-1 to serve as the stationary phase in the high-resolution gas chromatographic separation of benzene and cyclohexane or toluene and methylcyclohexane., (© 2022 Wiley-VCH GmbH.)

Birefringent crystals that can modulate the polarization of light play a significant role in modern optical devices including polarizing microscopes, optical isolators, and achromatic quarter-wave plates. To date, commercial birefringent crystals are exclusively limited to purely inorganic compounds. Here we report a new organic-inorganic hybrid halide, MLAPbBr 4 (MLA=melamine), which features a (110)-oriented layered perovskite structure. Although the 6s 2 lone-pair electrons of Pb 2+ cations are stereochemically inert, MLAPbBr 4 exhibits a birefringence of 0.322@550 nm, which exceeds those of all commercial birefringent crystals. The first-principles calculations reveal that this birefringence should be ascribed to the highly dislocated π-conjugation of MLA cations and high distortion of PbBr 6 octahedra. This work highlights the persistently neglected great potential of hybrid halide perovskites as birefringent crystals., (© 2022 Wiley-VCH GmbH.)

The separation of C 2 -C 3 alkyne/alkene mixtures is important but difficult work thanks to their similar physical and chemical properties. Crystalline porous materials with high alkyne adsorption and prominent separation selectivity of alkyne/alkene mixtures have been extensively investigated because of their energy-saving merits. Herein, we report a fluorinated hybrid microporous material (FJI-W1) that exhibits unexpected water and thermal stability. Gas sorption isotherms show that FJI-W1 has ultrahigh C 2 H 2 and C 3 H 4 adsorption capacities of 150 and 159 cm 3 /g, respectively. Furthermore, dynamic breakthrough experiments indicate that the intervals of breakthrough time between the two gases for 1:99 (v/v) C 2 H 2 /C 2 H 4 and 1:99 (v/v) C 3 H 4 /C 3 H 6 can be up to 230 and 600 min/g, respectively. Additionally, the tests with different flow rates and three-cycle breakthrough tests demonstrate that FJI-W1 has a remarkable C 2 -C 3 alkyne/alkene separation performance.

High-performance bi-functional materials are in urgent demand for the next-generation integrated optical devices. In this work, we successfully synthesized the first tricyanomelaminate with bi-functional optical responses, namely Cs 3 C 6 N 9 •H 2 O ( I ), from its analogue Na 3 C 6 N 9 •3H 2 O by a facile ion exchange method. In contrast to Na 3 C 6 N 9 •3H 2 O, I realizes an optimal arrangement of π -conjugated (C 6 N 9 ) 3- anion groups in its crystal structure. As a result, the second-order nonlinear optical (NLO) response is greatly enhanced from nearly zero of Na 3 C 6 N 9 •3H 2 O to ∼9.8 × KH 2 PO 4 of I . Furthermore, I exhibits a giant linear optical anisotropic response (i.e. birefringence) of 0.52 at the wavelength of 550 nm. Both responses are almost the largest among the inorganic compounds of π -conjugated rings, which indicates that I has great potential as a bi-functional optical crystal. Structural and theoretical analyses reveal the microscopic origin of excellent optical properties. This work would attract a lot of interest to the persistently neglected potential of tricyanomelaminates as linear optical and NLO crystals., Competing Interests: The authors declare that they have no conflicts of interest in this work., (© 2022 The Authors. Publishing Services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.)

Materials exhibiting aggregation-induced emission (AIE) behaviour enable strong emission in solid state and can respond to various external stimuli, which may facilitate the development of materials for optical sensing, bioimaging or optoelectronic devices. Herein, we use an AIE luminogen 2',5'-diphenyl-[1,1':4',1"-terphenyl]-4,4"-dicarboxylic acid as the ligand to prepare an AIEgen-based MOF (metal-organic framework) named FJI-H31. FJI-H31 exhibits bright luminescence under ambient conditions (under air and at room temperature), but almost no emission is observed under vacuum. Our investigation shows that the emission intensity displays a smooth and reversible enhancement with increased gas pressure, which may be attributed to the restriction of intramolecular motion brought by structural deformation under pressure stimulus. Unlike most pressure-responsive MOFs, the luminescence reverts to its original state once gas pressure recovers. By virtue of its unique optical properties, a luminescent MOF with sensing ability of gas-pressure is realized., (© 2022. The Author(s).)

2D van der Waals materials are widely explored for in-plane polarized light detection owing to their distinctive in-plane anisotropic feature. However, most of these polarized light-sensitive devices root in their low symmetry of in-plane structure and work depending on external power sources, which greatly impedes the simplification of integrated devices and sustainable development. Bulk photovoltaic effect (BPVE), which separates photoexcited carriers via built-in electric field without an external power source and shows an angle-dependence on light polarization, is promising for self-powered polarized light detection to break through the restriction of in-plane anisotropy. Herein, a 2D lead-free van der Waals perovskite (Cl-PMA) 2 CsAgBiBr 7 (1, Cl-PMA = 4-Chlorobenzylamine) is successfully designed through the dimension reduction strategy. 1 exhibits BPVE with an open-circuited photovoltage up to ≈0.5 V. Driven by the BPVE, self-powered in-plane polarized light detection with a large polarization ratio of 1.3 is obtained for 1. As far as it is known, the first in-plane polarized light detection in hybrid perovskites based on BPVE is realized here. This work highlights the strategy of designing lead-free hybrid perovskite with BPVE and opens an avenue for exploiting in-plane highly sensitive polarized light detection in 2D van der Waals materials., (© 2022 Wiley-VCH GmbH.)

Visible-infrared dual-modal light harvesting is crucial for various optoelectronic devices, particularly for solar cells and photodetectors. Hybrid metal-halide perovskites are recently emerging for visible-infrared dual-modal photodetection owing to their prominent multiphoton absorption and carrier transport performances. However, they work relying on an applied external power source or complicated heterostructures. It is still a difficult task to realize visible-infrared dual-modal self-powered photoresponse induced by a bulk photovoltaic effect (BPVE) in a single material. In this work, we constructed a polar multilayered perovskite, (Br-BA) 2 (EA) 2 Pb 3 Br 10 (BEP; EA + = ethylammonium, and Br-BA + = 4-brombutylammonium). Notably, the polar feature endows BEP with a BPVE. In addition, BEP presents a distinctive two-photon activity arising from the layered quantum-well structure. Benefitting from these striking characteristics, self-powered visible-infrared dual-modal photodetection is realized, and a direct self-powered detection of 800 nm light with a photocurrent of 2.1 nA cm -2 is achieved. This work will inspire the design of desired photoelectric materials with a BPVE for high-performance self-powered visible-infrared dual-modal photodetection.

Accurately designing and synthesizing new deep-ultraviolet (deep-UV) nonlinear optical (NLO) crystals that are limited by the so-called "200 nm wall" on their transparency windows remain challenging. On the basis of a bandgap-directed computer-aided material design approach, two new NLO sulfates, KMgSO 4 F and KZnSO 4 F, are designed and successfully synthesized. They feature three-dimensional frameworks closely related to the commercial NLO crystal, KTiOPO 4 (KTP). Remarkably, the transmittance spectrum based on a single crystal indicates that the transparency window of KZnSO 4 F is significantly blue-shifted to <190 nm from 350 nm for KTP. The microscopic origin of this significant transparent window blue shift is illustrated well by first-principles calculations. This work pushes the transparency windows of KTP-like NLO sulfates into the deep-UV spectral region for the first time and will pave a prospective way to the accurate design and synthesis of new deep-UV NLO materials.

Linear dichroic anisotropic photonic materials are highly attractive due to their great potentials in many applications, which in combination with the ferroelectric properties could broaden their research and applications. However, to date, the linear dichroism conversion phenomenon has not been observed in one-dimensional (1D) large-size single-crystal materials: in particular, lead-free perovskite ferroelectric crystals. Here, we propose a new ferroelectric design strategy: namely, partial organic cation substitution for precisely designing 1D polarization-sensitive perovskite ferroelectrics. As an example, the 1D mixed-cation perovskite ferroelectric ( n -propylammonium)(methylammonium)SbBr 5 was synthesized, which exhibits a fascinating ferroelectricity with a notable reversible polarization of 2.9 μC/cm 2 and a large ferroelectricity-driven polarization ratio of 6.9. Importantly, the single-crystalline photodetectors also exhibit superior optoelectronic anisotropic performances at the paraelectric phase, having a large photoelectric anisotropy ratio (∼35), an excellent polarization-sensitive dichroism ratio (∼1.31), highly sensitive detectivity up to ∼10 9 Jones, and a fast response rate (∼45/68 μs). This finding provides a significant and effective pathway for the targeted design of new functional lead-free linear dichroic anisotropic photonic ferroelectrics.

It remains a challenge to develop UV nonlinear optical (NLO) crystals that can achieve a desirable trade-off on UV absorption edge, second harmonic generation (SHG), and birefringence. Here we report a thiosulfate UV NLO crystal of a 2D van der Waals layered structure, [C(NH 2 ) 3 ] 2 SO 3 S. Remarkably, this thiosulfate realizes the desired trade-off, with a short absorption edge of 254 nm, a strong SHG response of approximately 2.8 times that of the benchmark KH 2 PO 4 , and a sufficient birefringence of 0.073 at the wavelength of 546 nm. In addition, it exhibits strong in-plane anisotropy of the SHG intensity. According to the first-principles calculations, the non- π -conjugated [SO 3 S] 2- anion is the dominant SHG functional gene, while the π -conjugated [C(NH 2 ) 3 ] + cation serves as the functional gene of birefringence. This is different from common UV NLO materials whose functionals of SHG and birefringence are the same. These findings indicate that combining different function genes may be an effective strategy to develop outstanding NLO materials with the desirable property trade-off.

Multiporous metal-organic frameworks (MOFs) have emerged as a subclass of highly crystalline inorganic-organic materials, which are endowed with high surface areas, tunable pores, and fascinating nanostructures. Heterostructured MOF-on-MOF composites are recently becoming a research hotspot in the field of chemistry and materials science, which focus on the assembly of two or more different homogeneous or heterogeneous MOFs with various structures and morphologies. Compared with one single MOF, the dual MOF-on-MOF composites exhibit unprecedented tunability, hierarchical nanostructure, synergistic effect, and enhanced performance. Due to the difference of inorganic metals and organic ligands, the lattice parameters in a, b, and c directions in the single crystal cells could bring about subtle or large structural difference. It will result in the composite material with distinct growth methods to obtain secondary MOF grown from the initial MOF. In this review, the authors wish to mainly outline the latest synthetic strategies of heterostructured MOF-on-MOFs and their derivatives, including ordered epitaxial growth, random epitaxial growth, etc., which show the tutorial guidelines for the further development of various MOF-on-MOFs., (© 2021 Wiley-VCH GmbH.)

Constructing supramolecular cages with multiple subunits via weak intermolecular interactions is a long-standing challenge in chemistry. So far, π-stacked supramolecular cages still remain unexplored. Here, we report a series of π-stacked cage based hierarchical self-assemblies. The π-stacked cage (π-MX-cage) is assembled from 16 [MXL] + ions (M = Mn 2+ , Co 2+ ; X = Br - , SCN - , Cl - ; and L = tris(2-benzimidazolylmethyl)amine) via 18 intermolecular π-stacking interactions. The tetrahedral cage, consisting of four [MXL] + ions as the vertexes and six pairs of [MXL] + ions as the edges, features 48 exterior N-H hydrogen bond donors for hydrogen bond formation with guest molecules. By variation of the M 2+ /X - pair, the π-MX-cage demonstrates unique versatility for incorporating a wide variety of species via different hydrogen-bonding modes during the assembly of hierarchical superstructures. In specific, the π-MnBr-cages encapsulate acetonitrile (CH 3 CN) or cis -1,3,5-cyclohexanetricarbonitrile ( cis -HTN) molecules in the central voids, while a core-shell tetrahedral inorganic cluster [Mn(H 2 O) 6 ]@([Mn(H 2 O) 4 ] 4 [Br 4 2- ] 6 ) (Mn@Mn 4 -cage) is captured within the interstitial regions between cages. The π-CoSCN-cages are capable of stabilizing reactive sulfur-containing species, such as S 2 O 4 2- , S 2 O 6 2- , and HSO 3 - ions, in the hierarchical superstructure. Finally, H 2 PO 4 - ions are incorporated between π-CoCl-cages, resulting in an inorganic mesoporous framework. These results provide insights into further exploring the chemistry and hierarchical assembly of supramolecular cages based on π-π stacking intermolecular interactions.

Mercury and cadmium are deemed to be the most harmful heavy metal ions for elimination due to their persistent bio-accumulative and bio-expanding toxic effects. Although many technologies have been developed for capturing Hg(II) and Cd(II) ions from aqueous solution, developing efficient and practical capature technology remains a big challenge. Metal-organic frameworks (MOFs) have been considered as the most promising adsorbents for Hg(II) and Cd(II) removal due to their high porosity and easy functionalization, and various of MOF-based adsorbents based on different synthetic strategies have been prepared and studied. In this article, the progresses of MOF-based absorbents for Hg(II) and Cd(II) capture are described according to the synthetic strategies and the types of functional groups, and the comparison and practical analysis of various adsorbents are also presented., (© 2021 The Chemical Society of Japan & Wiley-VCH GmbH.)

Despite borate-sulfates composed of isolated borate and sulfate groups have been discovered for more than one century, borosulfates of B-O-S bonding have not been synthesized until 2012 and their properties remain rarely explored. Here, we report a new borosulfate, namely LiRb 4 [B(SO 4 ) 4 ], which shows potential as a bran-new class of deep-UV nonlinear optical (NLO) material. Remarkably, according to the in situ single-crystal X-ray diffraction, LiRb 4 [B(SO 4 ) 4 ] undergoes successive first-order phase transitions with incommensurate structural modulations under room temperature and low temperature with (3 + 1)D superspace groups of X2(α0γ)0 and P2 1 (α0γ)0, respectively. The first-principle calculations and structural analyses reveal that NLO properties, phase transitions, and incommensurate modulations are closely related to the [B(SO 4 ) 4 ] 5- super-tetrahedral units with B-O-S bonding. We anticipate that the unprecedented coexistence of deep-UV transparency, NLO responses, and incommensurate structural modulations in one borosulfate will bring new possibilities to understand the underlying concepts of physics and chemistry in aperiodic materials., (© 2021 Wiley-VCH GmbH.)

Through a functional unit-transmutation strategy, a fatigue-free layered hybrid perovskite ferroelectric (C 6 H 5 CH 2 NH 3 ) 2 CsPb 2 Br 7 (BCPB) has been developed, which demonstrates stable spontaneous polarization (P s ) of 6.5 μC cm -2 and high Curie temperature up to 425 K. Meanwhile, BCPB shows splendid bulk photovoltaic effect (BPVE) properties with noticeable zero-bias photocurrent density (5 μA cm -2 ), and high on/off switching ratio of current (over 3×10 5 ); these merits even overmatch the most known ferroelectric semiconductor BiFeO 3 . The unique structure with self-regulated net electrical charged layers gives rise to the fatigue-free feature of P s and BPVE (no significant fatigue after 10 8 polarity switching cycles), promoting the potential applications of BCPB in photovoltaic non-volatile memories. This work offers an efficient approach for exploring fatigue-free semiconducting ferroelectrics as well as excavates their further applications in next-generation electronic devices., (© 2020 Wiley-VCH GmbH.)

Adsorption-based separation is an important technology for C 2 H 2 purification due to the environmentally friendly and energy-efficient advantage. In addition to the high selectivity of C 2 H 2 /CO 2 , the high uptake of C 2 H 2 also plays an important role in the separation progress. However, the trade-off between adsorption capacity and separation performance is still in a dilemma. Herein, we report a series of cage-like porous materials named FJI-H8-R (R=Me, Et, n Pr and i Pr) which all have high C 2 H 2 uptakes at 1 bar and 298 K. Dynamic breakthrough studies show that they all exhibit excellent C 2 H 2 /CO 2 separation performance. Particularly, FJI-H8-Me possesses a long breakthrough time up to 90 min g -1 . Additionally, Grand Canonical Monte Carlo (GCMC) simulation reveals that the suitable pore space and geometry contribute much to the excellent separation performance., (© 2021 Wiley-VCH GmbH.)

Herein we report a two-fold interpenetrating pillar-layer microporous material, whose framework severely shrinks after losing guest molecules and transforms into a stable nonporous one. More importantly, the guest-free framework has rarely seen temperature-dependent gate-opening behaviours for C2 gases around room temperature.

Metal-halide perovskites are recently emerging as the promising alternative for CPL detection owing to their CPL-sensitive property induced by chiral organics and efficient charge transport of inorganic frameworks. However, most of these reported chiral perovskites involve high concentrations of toxic Pb which will become the potential bottleneck for their further application. Herein, we successfully developed two lead-free halide double perovskites, [(R)-β-MPA] 4 AgBiI 8 ((R)-β-MPA=(R)-(+)-β-methylphenethylammonium, 1-R), and [(S)-β-MPA] 4 AgBiI 8 ((S)-β-MPA=(S)-(-)-β-methylphenethylammonium, 1-S). Circular dichroism measurements reveal that these perovskites exhibit notable chirality induced by organic cations to distinguish different polarization states of CPL photons. Significantly, they present unique chiral polar photovoltaic, and resulting self-powered CPL detection without an external power source is unprecedentedly achieved. Furthermore, an anisotropy factor up to 0.3 is acquired for the self-powered CPL detection, reaching the highest value among reported chiral perovskites. This work suggests hybrid double perovskites are promising photoelectronic candidates, and provides a new approach for exploring new "green" circularly polarized light-sensitive materials with high performance., (© 2020 Wiley-VCH GmbH.)

Despite much intense investigation on the C 2 H 2 /CO 2 separation, the trade-off between the adsorption capacity and separation selectivity is still tricky. To overcome the dilemma, we have rationally synthesized an ultra-stable fluorinated hybrid porous material SIFSIX-Cu-TPA with the ith-d topology. Completely differing from the famous pillar-layer fluorinated materials, SIFSIX-Cu-TPA possesses a unique pillar-cage structure, in which the SiF 6 2- anions cross-link two adjacent metal nodes as pillars to stabilize the three-dimensional framework constructed by icosahedral and tetrahedral cages. As anticipated, SIFSIX-Cu-TPA has high BET surface area (1330 m 2  g -1 ) as well as high C 2 H 2 uptake (185 cm 3  g -1 at 298 K and 1 bar). At the same time, due to the obvious difference in the adsorption performance of CO 2 and C 2 H 2 especially in the low pressure area, SIFSIX-Cu-TPA also exhibits an excellent C 2 H 2 /CO 2 separation performance (breakthrough time up to 68 min g -1 at 298 K and 1 bar)., (© 2021 Wiley-VCH GmbH.)

Lanthanide-doped inorganic nanocrystals, possessing superior luminescence performance and photochemical stability, have attracted considerable attention due to their promising biological applications such as in bioimaging, biodetection, biotherapeutics and temperature sensing. Great progress has been made in achieving distinct and tailored optical properties for these functional nanocrystals in the past few decades. In this feature article, we summarize our recent advances in the realization of desirable and tunable luminescence for lanthanide-doped inorganic nanocrystals through local structure engineering that includes two main strategies, namely, externally morphological architecture design and intrinsically crystal structure regulation. As for the externally morphological architecture design, distinct optical performance achieved in lanthanide-doped nanocrystals with varied morphologies like core-shell, hollow and ultrasmall nanoarchitectures is summarized. With regard to the intrinsically crystal structure regulation, the tunable upconversion luminescence intensity and red-to-green ratio of Er 3+ for Yb 3+ /Er 3+ -doped nanocrystals and the consequent biodegradable nanocrystals are discussed, with an emphasis on the origin underlying the crystal-structure-dependent upconversion luminescence. Multifarious biological applications, including heterogeneous biodetection based on core-shell nanocrystals, homogeneous biodetection based on ultrasmall nanocrystals, superior nanothermometer based on hollow nanocrystals and in vivo bioimaging based on biodegradable nanocrystals, are briefly reviewed. Current challenges and future opportunities for lanthanide-doped inorganic nanocrystals for biological applications are also provided in the end.

Four lanthanide metal-organic frameworks (Ln-MOFs), namely {[Me 2 NH 2 ][LnL]·2H 2 O} n (Ln = Eu 1 , Tb 2 , Dy 3 , Gd 4 ), have been constructed from a new tetradentate ligand 1-(3,5-dicarboxylatobenzyl)-3,5-pyrazole dicarboxylic acid (H 4 L). These isostructural Ln-MOFs, crystallizing in the monoclinic P 2 1 /c space group, feature a 3D structure with 7.5 Å × 9.8 Å channels along the b axis and the point symbol of {4 10 .6 14 .8 4 } {4 5 .6} 2 . The framework shows high air and hydrolytic stability, which can keep stable after exposed to humid air for 30 days or immersed in water for seven days. Four MOFs with different lanthanide ions (Eu 3+ , Tb 3+ , Dy 3+ , and Gd 3+ ) ions exhibit red, green, yellow, and blue emissions, respectively. The Tb-MOF emitting bright green luminescence can selectively and rapidly (<40 s) detect Fe 3+ in aqueous media via a fluorescence quenching effect. The detection shows excellent anti-inference ability toward many other cations and can be easily recognized by naked eyes. In addition, it can also be utilized as a rapid fluorescent sensor to detect acetone solvent as well as acetone vapor. Similar results of sensing experiments were observed from Eu-MOF. The sensing mechanism are further discussed.

Polarization-sensitive photodetection is central to optics applications and has been successfully demonstrated in photodetectors of two-dimensional (2D) materials, such as layered hybrid perovskites; however, achieving high polarization sensitivity in such a photodetector remains extremely challenging. Here, for the first time, we demonstrate a high-performance polarization-sensitive photodetector using single-crystalline 2D/3D perovskite heterostructure, namely, (4-AMP)(MA) 2 Pb 3 Br 10 /MAPbBr 3 (MA = methylammonium; 4-AMP = 4-(aminomethyl)piperidinium), which exhibits ultrahigh polarization sensitivity up to 17.6 under self-driven mode. To our knowledge, such a high polarization selectivity has surpassed all of the reported perovskite-based devices, and is comparable to, or even better than, the traditional inorganic heterostructure-based photodetectors. Further studies reveal that the built-in electric field formed at the junction can spatially separate the photogenerated electrons and holes, reducing their recombination rate and thus enhancing the performance for polarization-sensitive photodetection. This work provides a new source of polarization-sensitive materials and insights into designing novel optoelectronic devices., (© The Author(s) 2021. Published by Oxford University Press on behalf of China Science Publishing & Media Ltd.)