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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.)

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.)

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.)

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.)

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.)

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.)

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.)

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.)

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.)

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.)

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.)

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.)

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.)

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.)

Induction of chirality from an achiral assembly system remains a huge challenge related to the origin of life. Here, induction of chirality in a metal-organic framework (MOF) built from achiral precursors has been realized. Assembling achiral H 3 BTB ligands and Zn II /Cd II clusters leads to a 2D coordination polymer (FJI-H16), while introduction of achiral pyridine into such assembly system leads to a 3D chiral MOF (FJI-H27 (M) or (P)). The driven force for chiral generation has been proved to be a pyridine participated kinetic-control assembly process, which can be controlled by changing the amount of pyridine and temperature, from no induction to partial induction to complete induction. The chiral generation process has been identified in detail through a pyridine-involved key intermediate (FJI-H28). The targeted modification of pyridine can selectively lead to FJI-H27 (M) or FJI-H27 (P), making the chiral orientation and distribution of bulk FJI-H27 samples can be controlled. Our work not only represents a new chiral induction process that may relate to the chiral origin in nature, but also firstly reveals how achiral external stimuli generate chirality from achiral precursors, and offers a guide for rational preparation of chiral MOFs., (© 2020 Wiley-VCH GmbH.)

Multiphoton absorption (MPA) has been utilized for important technological applications. High-order multiphoton harvesting (e.g., five-photon absorption, 5PA) exhibits unique properties that could benefit biophotonics. Within this field, perovskite oxide ferroelectrics (e.g., BaTiO 3 ) enable low-order optical nonlinearities of 2PA/3PA processes. However, it is challenging to obtain efficient, high-order 5PA effects. Herein, for the first time, giant and broadband MPA properties are presented in the 2D hybrid perovskite ferroelectric (IA) 2 (MA) 2 Pb 3 Br 10 (1; IA = isoamylammonium and MA = methylammonium), where multiphoton-excited optical nonlinearities related to different MPA mechanisms over a broadband range of 550-2400 nm are observed. Strikingly, its 5PA absorption cross-section (σ 5 ) reaches up to 1.2 × 10 -132 cm 10 s 4 photon -4 (at 2400 nm), almost 10 orders larger than some state-of-the-art organic molecules and a record-high value among all known ferroelectrics. This unprecedented 5PA effect results from the quantum-confined motif of inorganic trilayer sheets (wells) and organic cations (barriers) in 1. Moreover, its large ferroelectric polarization of 5 µC cm -2 could promote modulation of MPA effects under external electric fields. As far as it is known, this is the first report on giant, broadband high-order MPA properties in ferroelectrics, which provides potential, novel electric-ordered materials for next-generation biophotonic applications., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Although two-dimensional (2D) metal-halide double perovskites display versatile physical properties due to their huge structural compatibility, room-temperature ferroelectric behavior has not yet been reported for this fascinating family. Here, we designed a room-temperature ferroelectric material composed of 2D halide double perovskites, (chloropropylammonium) 4 AgBiBr 8 , using an organic asymmetric dipolar ligand. It exhibits concrete ferroelectricity, including a Curie temperature of 305 K and a notable spontaneous polarization of ≈3.2 μC cm -2 , triggered by dynamic ordering of the organic cation and the tilting motion of heterometallic AgBr 6 /BiBr 6 octahedra. Besides, the alternating array of inorganic perovskite sheets and organic cations endows large mobility-lifetime product (μτ=1.0×10 -3  cm 2  V -1 ) for detecting X-ray photons, which is almost tenfold higher than that of CH 3 NH 3 PbI 3 wafers. As far as we know, this is the first study on an X-ray-sensitive ferroelectric material composed of 2D halide double perovskites. Our findings afford a promising platform for exploring new ferroelectric materials toward further device applications., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Facile preparation of low-cost electrocatalysts for efficient oxygen evolution reaction (OER) remains a big challenge. Herein, a novel strategy for ultrafast (20 s) transformation of bulk metal-organic frameworks (MOFs) into ultrathin metal oxyhydroxide nanosheets for efficient OER has been developed. For two isomeric MOFs (FJI-H25Fe and FJI-H25FeCo), only the metastable FJI-H25FeCo bulk can immediately transform into FeCo-oxyhydroxides nanosheets through electric-field assisted hydrolysis. The potential evolution process from MOF bulk to FeCo-oxyhydroxides nanosheets has been investigated in detail. The as-made nanosheets exhibit excellent OER performances, showing an extremely low overpotential of 231 mV at the current density of 10 mA cm -2 , a relatively small Tafel slope of 42 mV dec -1 , and long-term durability of at least 30 h. This work not only provides a novel strategy for facile preparation of low-cost and efficient OER electrocatalysts, but also represents a new way for preparation of metal oxyhydroxides nanosheets with good crystallinity and morphology, and a fresh method for mild synthesis of nanosized derivatives from MOF materials., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Trivalent lanthanide (Ln 3+ )-doped hollow upconversion nanocrystals (UCNCs) usually exhibit unique optical performance that cannot be realized in their solid counterparts, and thus have been receiving tremendous interest from their fundamentals to diverse applications. However, all currently available Ln 3+ -doped UCNCs are solid in appearance, the preparation of hollow UCNCs remains nearly untouched hitherto. Herein, a class of UCNCs based on Yb 3+ /Er 3+ -doped tetralithium zirconium octafluoride (Li 4 ZrF 8 :Yb/Er) featuring 2D layered crystal lattice is reported, which makes the fabrication of hollow UCNCs with a peasecod-like shape possible after Ln 3+ doping. By employing the first-principle calculations, the unique peasecod-like hollow nanoarchitecture primarily associated with the hetero-valence Yb 3+ /Er 3+ doping into the 2D layered crystal lattice of Li 4 ZrF 8 matrix is revealed. Benefiting from this hollow nanoarchitecture, the resulting Li 4 ZrF 8 :Yb/Er UCNCs exhibit an abnormal green upconversion luminescence in terms of the population ratio between two thermally coupled states ( 2 H 11/2 and 4 S 3/2 ) of Er 3+ relative to their solid Li 2 ZrF 6 :Yb/Er counterparts, thereby allowing to prepare the first family of hollow Ln 3+ -doped UCNCs as supersensitive luminescent nanothermometer with almost the widest temperature sensing range (123-800 K). These findings described here unambiguously pave a new way to fabricate hollow Ln 3+ -doped UCNCs for numerous applications., Competing Interests: The authors declare no conflict of interest., (© 2020 The Authors. Published by WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.)

Birefringent materials, which can modulate the polarization of light, are almost exclusively limited to oxides. Peroxides have long been overlooked as birefringent materials, because they are usually not stable in air. Now, the first peroxide birefringent material Rb 2 VO(O 2 ) 2 F is reported, the single crystals of which keep transparency after being exposed in the air for two weeks. Interestingly, Rb 2 VO(O 2 ) 2 F does not feature an optimal anisotropic structure, but its birefringence (Δn=0.189 at 546 nm) exceeds those of the majority of oxides. According to the first-principles calculations, this exceptional birefringence should be attributed to the strong electronic interactions between localized π orbital of O 2 2- anions and V 5+ 3d orbitals, which may be also favorable to the stability in the air for Rb 2 VO(O 2 ) 2 F. These findings distinguish peroxides as a brand-new class of birefringent materials that may possess birefringence superior to the traditional oxides., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Halide double perovskites have recently emerged as a promising environmentally friendly optoelectronic and photovoltaic material for their inherent thermodynamic stability, high defect tolerance, and appropriate band gaps. However, to date, no ferroelectric material based on halide double perovskites has been discovered. Herein, by hetero-substitution of lead and cation intercalation of n-propylamine, the first halide double perovskite ferroelectric, (n-propylammonium) 2 CsAgBiBr 7 (1), is reported and it exhibits distinct ferroelectricity with a notable saturation polarization of about 1.5 μC cm -2 . More importantly, single-crystal photodetectors of 1 exhibit extraordinary performance with containing high on/off ratios of about 10 4 , fast response rates of 141 μs, and detectivity as high as 5.3×10 11  Jones. This finding opens a new way to design high-performance perovskite ferroelectrics, and provides a viable approach in the search for stable and lead-free optoelectronic materials as an alternative to the lead-containing system., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Antimony(III) borates with a stereochemical active lone pair remained unknown, although the first antimony borate was reported more than twenty years ago. Now, the first antimony(III) borate in a closed system is successfully synthesized, namely SbB 3 O 6 . Remarkably, SbB 3 O 6 not only exhibits an exceptional linear optical response, that is, birefringence of Δn=0.290 at the wavelength of 546 nm, which is the largest among borates, but also has a strong nonlinear optical response of 3.5 times larger than the benchmark KH 2 PO 4 , exceeding those of most borates. Theoretical calculations reveal that the coexistence of strong linear and nonlinear optical responses in SbB 3 O 6 should be attributable to the synergistic effect of π-conjugated B-O anionic groups and Sb 3+ with stereochemically active lone pair. This work provides a new class of optical bi-functional materials with potential prospects in integrated optical devices., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

3D perovskite CsPbBr 3 has recently taken a blooming position for optoelectronic applications. However, due to the lack of natural anisotropy of optical attributes, it is a great challenge to fulfil polarization-sensitive photodetection. Here, for the first time, we exploited dimensionality reduction of CsPbBr 3 to tailor a 2D-multilayered hybrid perovskite, (TRA) 2 CsPb 2 Br 7 (1, in which TRA is (carboxy)cyclohexylmethylammonium), serving as a potential polarized-light detecting candidate. Its unique quantum-confined 2D structure results in intrinsic anisotropy of electrical conductivity, optical absorbance, and polarization-dependent responses. Particularly, it exhibits remarkable dichroism with the photocurrent ratio (I pc /I pa ) of ≈2.1, being much higher than that of the isotropic CsPbBr 3 crystal and reported CH 3 NH 3 PbI 3 nanowire (≈1.3), which reveals its great potentials for polarization-sensitive photodetection. Further, crystal-based detectors of 1 show fascinating responses to the polarized light, including high detectivity (>10 10 Jones), fast responding time (≈300 μs), and sizeable on/off current ratios (>10 4 ). To our best knowledge, this is the first study on 2D Cs-based hybrid perovskite exhibiting strong polarization-sensitivity. The work highlights an effective pathway to explore new polarization sensitive candidates for hybrid perovskites and promotes their future electronic applications., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Polarized light detection is attracting increasing attention for its wide applications ranging from optical switches to high-resolution photodetectors. Two-dimensional (2D) hybrid perovskite-type ferroelectrics combining inherent light polarization dependence of bulk photovoltaic effect (BPVE) with excellent semiconducting performance present significant possibilities. Now, the BPVE-driven highly sensitive polarized light detection in a 2D trilayered hybrid perovskite ferroelectric, (allyammonium) 2 (ethylammonium) 2 Pb 3 Br 10 (1), is presented. It shows a superior BPVE with near-band gap photovoltage of ca. 2.5 V and high on/off switching ratio of current (ca. 10 4 ). Driven by the superior BPVE, 1 exhibits highly sensitive polarized light detection with a polarization ratio as high as ca. 15, which is far more beyond than those of structural anisotropy-based monocomponent devices. This is the first realization of BPVE-driven polarized light detection in hybrid perovskite ferroelectrics., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The species diversity of silicon (including traditional tetrahedral coordinated silicon and hypervalent penta- and hexa-coordinate silicon) gives rise to the structural richness and diverse properties of silicates. Among these silicon species, hypervalent silicon is very rare, not to mention almost unexplored mixed-anion hypervalent fluoroxosilicate species. In this work, we successfully obtained a mixed-anion fluorooxosilicophosphate Na4Si2PO4F9 consisting of two uncommon hypervalent fluoroxosilicate species, namely, trans-SiO2F4 species and SiOF 5 species. To the best of our knowledge, such hypervalent silicon species are reported for the first time in inorganic compounds. Remarkably, the coexistence of two distinct hypervalent fluoroxosilicate species in one compound is somewhat conflicted with Pauling's parsimony rule, but it indeed achieves an unlikely connection by PO 4 and our phonon dispersion calculation confirms the structure stability of Na 4 Si 2 PO 4 F 9 . Temperature-dependent conductivity measurements show that Na 4 Si 2 PO 4 F 9 is a promising solid ionic conductor with a high conductivity of 4.0×10 -5  S⋅cm -1 at 700 K and a low active energy of about 53.1 KJ⋅mol -1 . This work will enrich the structure chemistry of silicates and may provide a new platform for solid ionic batteries., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A flexible two-fold interpenetrated indium metal-organic framework InOF-23, featuring one-dimensional micro-sized channels decorated by exposed N groups, was successfully synthesized. Interestingly, InOF-23 displays unique dynamic responses to different gases (N 2 , Ar, and CO 2 ) at low and room temperatures, which indicates that it can be a good candidate for gas adsorption and separation. Furthermore, the high efficiency detection for p-nitroaniline (pNA) makes InOF-23 a potential chemosensor for nitroaromatic explosives., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Self-powered photodetection driven by ferroelectric polarization has shown great potential in next-generation optoelectronic devices. Hybrid perovskite ferroelectrics that combine polarization and semiconducting properties have a promising position within this portfolio. Herein, we demonstrate the realization of self-powered photodetection in a new developed biaxial ferroelectric, (EA) 2 (MA) 2 Pb 3 Br 10 (1, EA is ethylammonium and MA is methylammonium), which displays high Curie temperature (375 K), superior spontaneous polarization (3.7 μC cm -2 ), and unique semiconducting nature. Strikingly, without an external energy supply, 1 exhibits an direction-selectable photocurrent with fascinating attributes including high photocurrent density (≈4.1 μA cm -2 ), high on/off switching ratio (over 10 6 ), and ultrafast response time (96/123 μs); such merits are superior to those of the most active ferroelectric oxide BiFeO 3 . Further studies reveal that strong inversion symmetry breaking in 1 provides a desirable driving force for carrier separation, accounting for such electrically tunable self-powered photoactive behaviors. This work sheds light on exploring new multifunctional hybrid perovskites and advancing the design of intelligent photoelectric devices., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

2D hybrid perovskites have shown great promise in the photodetection field, due to their intriguing attributes stemming from unique structural architectures. However, the great majority of detectors based on this 2D system possess a relatively low response speed (≈ms), making it extremely urgent to develop new candidates for superfast photodetection. Here, a new organic-inorganic hybrid perovskite, (PA) 2 (FA)Pb 2 I 7 (EFA, where PA is n-pentylaminium and FA is formamidine), which features the 2D Ruddlesden-Popper type perovskite framework that is composed of the corner-sharing PbI 6 octahedra is reported. Significantly, photodetectors fabricated on highly oriented thin films, which exhibit a perfect orientation parallel to 2D inorganic perovskite layers, exhibit a superfast response time up to ≈2.54 ns. To the best of the knowledge, this figure-of-merit catches up with that of the top-ranking commercial materials, and sets a new record for 2D hybrid perovskite photodetectors. Moreover, extremely high photodetectivity (≈1.73 × 10 14 Jones, under an incident power intensity of ≈46 µW cm -2 ), considerable switching ratios (>10 3 ), and low dark current (≈10 pA) are also achieved in the detector, indicating its great potential for high-efficiency photodetection. These results shed light on the possibilities to explore new 2D candidates for assembling future high-performance optoelectronic devices., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

All-inorganic cesium lead halide perovskite nanocrystals (NCs) with different dimensionalities have recently fascinated the research community due to their extraordinary optoelectronic performance such as tunable bandgaps over the entire visible spectral region. However, compared to well-developed 3D CsPbX 3 perovskites (X = Cl, Br, and I), the bandgap tuning in 0D Cs 4 PbX 6 perovskite NCs remains an arduous task. Herein, a simple but valid strategy is proposed to tailor the insulator bandgap (≈3.96 eV) of Cs 4 PbBr 6 NCs to the blue spectral region by changing the local coordination environment of isolated [PbBr 6 ] 4- octahedra in the Cs 4 PbBr 6 crystal through Sn cation doping. Benefitting from the unique Pb 2+ -poor and Br - -rich reaction environment, the Sn cation is successfully introduced into the Cs 4 PbBr 6 NCs, forming coexisting point defects comprising substitutional Sn Pb and interstitial Br i , thereby endowing these theoretically nonluminescent Cs 4 PbBr 6 NCs with an ultranarrow blue emission at ≈437 nm (full width at half maximum, ≈12 nm). By combining the experimental results with first-principles calculations, an unusual electronic dual-bandgap structure, comprising the newly emerged semiconducting bandgap of ≈2.87 eV and original insulator bandgap of ≈3.96 eV, is found to be the underlying fundamental reason for the ultranarrow blue emission., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Selective probing of one molecule from one class of similar molecules is highly challenging due to their similar chemical and physical properties. Herein, a novel metal-organic framework FJI-H15 with flexible porous cages has been designed and synthesized, which can specifically recognize ethylbenzene with ultrahigh enhancement efficiency from a series of alkyl-aromatics, in which an unusual size-dependent interaction has been found and proved. It can also selectively detect phenolic-nitroaromatics among a series of nitroaromatics based on energy transfer and electrostatic interactions. Such unusual specificity and variable mechanisms responding to different types of molecules have not yet been reported, which will provide a new strategy for the development of more effective chemosensors based on MOFs for probing small structural differences in molecules., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Fast switching of spontaneous polarization (P s ) is one of the most essential requirements for ferroelectrics used in the field of data storage. However, in contrast to inorganic counterparts, the low operating frequency (<500 Hz) for molecular ferroelectrics severely hinders their large-scale applications. Herein, for the first time, we achieved the room-temperature fastest switching of the P s in a new molecular ferroelectric, N-methylmorpholinium trinitrophenolate (1), which displays notable ferroelectricity (P s =3.2 μc cm -2 ). Strikingly, electric polarizations of 1 have been switched under a record-high frequency of 263 kHz, and this performance remains stable without any obvious fatigue after ca. 2×10 5 switching cycles. To our knowledge, 1 is the first organic ferroelectric to switch polarization at such a high operating frequency, exceeding the majority of organic ferroelectrics, which opens up new possibilities for its potential in the field of non-volatile memory., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Cesium-lead halide perovskites (e.g. CsPbBr 3 ) have gained attention because of their rich physical properties, but their bulk ferroelectricity remains unexplored. Herein, by alloying flexible organic cations into the cubic CsPbBr 3 , we design the first cesium-based two-dimensional (2D) perovskite ferroelectric material with both inorganic alkali metal and organic cations, (C 4 H 9 NH 3 ) 2 CsPb 2 Br 7 (1). Strikingly, 1 shows a high Curie temperature (T c =412 K) above that of BaTiO 3 (ca. 393 K) and notable spontaneous polarization (ca. 4.2 μC cm -2 ), triggered by not only the ordering of organic cations but also atomic displacement of inorganic Cs + ions. To our knowledge, such a 2D bilayered Cs + -based metal-halide perovskite ferroelectric material with inorganic and organic cations is unprecedented. 1 also shows photoelectric semiconducting behavior with large "on/off" ratios of photoconductivity (>10 3 )., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We evaluated the individual atom contributions to the second harmonic generation (SHG) coefficients of LiCs 2 PO 4 (LCPO) by introducing the partial response functionals on the basis of first principles calculations. The SHG response of LCPO is dominated by the metal-cation-centered groups CsO 6 and LiO 4 , not by the nonmetal-cation-centered groups PO 4 expected from the existing models and theories. The SHG coefficients of LCPO are determined mainly by the occupied orbitals O 2p and Cs 5p as well as by the unoccupied orbitals Cs 5d and Li 2p. For the SHG response of a material, the polarizable atomic orbitals of the occupied and the unoccupied states are both important., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A series of flexible MOFs (PCN-605, PCN-606, and PCN-700) are synthesized and applied to reversible bromine encapsulation and release. The chemical stability of these Zr-MOFs ensures the framework's integrity during the bromine adsorption, while the framework's flexibility allows for structural adaptation upon bromine uptake to afford stronger host-guest interactions and therefore higher bromine adsorption capacities. The flexible MOFs act as bromine-nanocontainers which elongate the storage time of volatile halides under ambient conditions. Furthermore, the bromine pre-adsorbed flexible MOFs can be used as generic bromine sources for bromination reactions giving improved yields and selectivities under ambient conditions when compared with liquid bromine., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Two-dimensional (2D) layered hybrid perovskites have shown great potential in optoelectronics, owing to their unique physical attributes. However, 2D hybrid perovskite ferroelectrics remain rare. The first hybrid ferroelectric with unusual 2D multilayered perovskite framework, (C 4 H 9 NH 3 ) 2 (CH 3 NH 3 ) 2 Pb 3 Br 10 (1), has been constructed by tailored alloying of the mixed organic cations into 3D prototype of CH 3 NH 3 PbBr 3 . Ferroelectricity is created through molecular reorientation and synergic ordering of organic moieties, which are unprecedented for the known 2D multilayered hybrid perovskites. Single-crystal photodetectors of 1 exhibit fascinating performances, including extremely low dark currents (ca. 10 -12  A), large on/off current ratios (ca. 2.5×10 3 ), and very fast response rate (ca. 150 μs). These merits are superior to integrated detectors of other 2D perovskites, and compete with the most active CH 3 NH 3 PbI 3 ., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A robust hydrogen-bonded organic framework HOF-TCBP (H 4 TCBP=3,3',5,5'-tetrakis-(4-carboxyphenyl)-1,1'-biphenyl) has been successfully constructed and structurally characterized. It possesses a permanent 3D porous structure with a 5-fold interpenetrated dia topological network. This activated HOF-TCBP has a high BET surface area of 2066 m 2  g -1 and is capable of highly selective adsorption and separation of light hydrocarbons under ambient conditions. It shows excellent thermal stability, as demonstrated by PXRD experiments and N 2 adsorption tests. Practical use of HOF-TCBP is facilitated by the ease of its preparation and renewal through rotary evaporation., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Nitrates have long been ignored for practical uses as nonlinear optical (NLO) materials because they are usually very easy to dissolve in water; despite this, the π-conjugated [NO 3 ] - is among the most desirable NLO-active structural units. The cooperation of three structural chromophores, namely, Bi 3 O 6 OH short chains with 6s 2 lone pair electrons, distorted TeO 6 octahedra with d 10 electrons, and π-conjugated [NO 3 ] - triangles, generates a new nitrate NLO material, Bi 3 TeO 6 OH(NO 3 ) 2 , which exhibits an enhanced phase-matchable NLO response of three times that of KH 2 PO 4 (3×KH 2 PO 4 ), exceeding those of most nitrate NLO materials. Remarkably, the new material did not show obvious weight loss and degeneration of NLO response after being dipped in de-ionized water for 24 h, indicating that it is highly resistant to water. Theoretical calculations reveal that foreign water molecules cannot stably stay in the crystal lattice of Bi 3 TeO 6 OH(NO 3 ) 2 . These findings highlight the introduction of diverse chromophores into the nitrate systems as an effective approach for developing practical nitrate NLO materials that are of high water-resistance and good optical performance., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A temperature- and anion-induced coordination-driven self-assembly system based on a dynamic Ag 6 L 4 metallocage was developed. Induced by SbF 6 - anions, both kinetically controlled [Ag 3 L 2 (SbF 6 ) 3 ] n and thermodynamically controlled [Ag 2 L 2 (SbF 6 ) 2 ] n can be reassembled from discrete Ag 6 L 4 (SbF 6 ) 6 metallocages at 30 °C, and increasing the temperature to 40 °C results in selective inhibition of the kinetic product. Under the influence of BF 4 - anions, dynamic Ag 6 L 4 (BF 4 ) 6 metallocages self-assemble into the thermodynamically controlled polycage at 25 °C, and lowing the temperature to 0 °C leads to selective inhibition of the thermodynamic product. Thus, both kinetically and thermodynamically controlled assembly processes in a dynamic system can be selectively driven by suitable external stimuli., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)