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n‐C4H10 and iso‐C4H10 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‐C4H10 and iso‐C4H10 in one‐step separation process, developing iso‐C4H10‐exclusion adsorbents with high n‐C4H10 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‐C4H10 enter the pore and accommodate a large amount of n‐C4H10 simultaneously. Adsorption isotherms reveal that SIFSIX‐Cu‐TPA not only completely excludes iso‐C4H10 in a wide temperature range, but also exhibits a very high n‐C4H10 adsorption capacity of 94.2 cm3 g−1 at 100 kPa and 298 K, which is the highest value among iso‐C4H10‐exclusion‐type adsorbents. Breakthrough experiments show that SIFSIX‐Cu‐TPA has excellent n/iso‐C4H10 separation performance and can achieve a record‐high productivity of iso‐C4H10 (3.2 mol kg−1) with high purity (>99.95 %) as well as 3.0 mol kg−1 of n‐C4H10 (>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. [ABSTRACT FROM AUTHOR]

The one‐step efficient separation of high‐purity C2H4 from C2H4/C2H6 mixtures by hydrogen‐bonded organic frameworks (HOFs) faces two problems: lack of strategies for constructing stable pores in HOFs and how to obtain high C2H6 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 C2H4/C2H6 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 C2H6/C2H4. 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 C2H6/C2H4 feed gas to obtain polymer‐grade C2H4 in one step even under high‐humidity conditions. [ABSTRACT FROM AUTHOR]

H2O2 is a widely used eco‐friendly oxidant and a potential energy carrier. Photocatalytic H2O2 production from water and O2 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 H2O2 photoproduction performance under pure water and open air without any additives. CuBr‐dptz exhibits a H2O2 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 O2. 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 H2O2 production in such challenging conditions, which provides a new pathway for the development of portable in situ H2O2 photosynthesis devices. [ABSTRACT FROM AUTHOR]

Because C2H4 plays an essential role in the chemical industry, economical and energy‐efficient separation of ethylene (C2H4) from ethane (C2H6) is extremely important. With the exception of energy‐intensive cryogenic distillation, there are few one‐step methods to obtain polymer‐grade (≥99.95 % pure) C2H4 from C2H4/C2H6 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 C2H6 rather than C2H4 between 273 and 303 K. Practical breakthrough experiments with C2H4 containing 1 % C2H6 have shown that FJI‐H11‐Me(des) can realize the acquisition in one‐step of polymer‐grade, 99.95 % pure C2H4 under various conditions including different gas flow rates, temperatures and relative humidity. [ABSTRACT FROM AUTHOR]

Adsorption‐based separation is an important technology for C2H2 purification due to the environmentally friendly and energy‐efficient advantage. In addition to the high selectivity of C2H2/CO2, the high uptake of C2H2 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, nPr and iPr) which all have high C2H2 uptakes at 1 bar and 298 K. Dynamic breakthrough studies show that they all exhibit excellent C2H2/CO2 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. [ABSTRACT FROM AUTHOR]

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]4AgBiI8 ((R)‐β‐MPA=(R)‐(+)‐β‐methylphenethylammonium, 1‐R), and [(S)‐β‐MPA]4AgBiI8 ((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. [ABSTRACT FROM AUTHOR]

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 H3BTB ligands and ZnII/CdII 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. [ABSTRACT FROM AUTHOR]

Abstract: Cesium‐lead halide perovskites (e.g. CsPbBr3) have gained attention because of their rich physical properties, but their bulk ferroelectricity remains unexplored. Herein, by alloying flexible organic cations into the cubic CsPbBr3, we design the first cesium‐based two‐dimensional (2D) perovskite ferroelectric material with both inorganic alkali metal and organic cations, (C4H9NH3)2CsPb2Br7 (1). Strikingly, 1 shows a high Curie temperature (Tc=412 K) above that of BaTiO3 (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 (>103). [ABSTRACT FROM AUTHOR]

Abstract: We evaluated the individual atom contributions to the second harmonic generation (SHG) coefficients of LiCs2PO4 (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 CsO6 and LiO4, not by the nonmetal‐cation‐centered groups PO4 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. [ABSTRACT FROM AUTHOR]

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, (C4H9NH3)2(CH3NH3)2Pb3Br10 ( 1), has been constructed by tailored alloying of the mixed organic cations into 3D prototype of CH3NH3PbBr3. 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. 2.5×103), 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 CH3NH3PbI3. [ABSTRACT FROM AUTHOR]

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 [NO3]− is among the most desirable NLO-active structural units. The cooperation of three structural chromophores, namely, Bi3O6OH short chains with 6s2 lone pair electrons, distorted TeO6 octahedra with d10 electrons, and π-conjugated [NO3]− triangles, generates a new nitrate NLO material, Bi3TeO6OH(NO3)2, which exhibits an enhanced phase-matchable NLO response of three times that of KH2PO4 (3×KH2PO4), 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 Bi3TeO6OH(NO3)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. [ABSTRACT FROM AUTHOR]