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Stimuli-responsive coordination polymers (CPs) are among one of the most prolific research areas in developing the next-generation functional materials. Their capability of being accurately excited by particular external changes with pre-determined and observable/characterizable behaviors correspond, are the so called “stimuli” and “responsive”. Abundant types of CP compounds, especially metal-organic frameworks (MOFs), are of rocketing interest owing to their compositional diversity, structural tunability, and in essence their highly engineerable functionality. This present review is aimed to sketch several common types of stimulation and the corresponding responses for CPs, accompanied with the broad logic and mechanisms underneath. And further from the aspect of material revolution, some representative progresses together with the latest advances of CP-based materials in various fields are covered in attempt to display a broader picture towards the possible prospects of this topic.

Being an emerging family of crystalline porous materials, hydrogen-bonded organic frameworks (HOFs) are types of ordered supramolecular structures that constructed from organic linkers (including those with organometallic units) via mainly hydrogen bonds. HOFs have now attracted increasing attention in various fields, owing to their valued features such as mild synthetic condition, convenient purification/recovery processes, high processibility and diverse functionality. Great potentials have emerged for HOFs in the field of adsorption and separation, especially for the purification of light hydrocarbons that are crucial to the petrochemical industry. Their practical applications, however, is limited as it is rather difficult to maintain their porous architectures only through hydrogen bonds after removing the lattice solvent molecules. Several types of strategies have hence been developed to solve the issue of HOF structure fragility, including introduction of stronger/different forms of intermolecular interactions, adoption of monomers with rigid backbones, integration of appropriate structural interpenetrations, formation of the cross-linked structures, etc. In this review, the common strategies for constructing HOFs and the important role of each method in enhancing the structural stability of HOFs are briefly introduced. Then, the application of robust porous HOFs in various gases adsorptions and separations is carefully summarized, as well as its mechanism is analyzed in detail from the perspective of supramolecular interactions among the frameworks and gas molecules. The current challenges and the future perspectives for HOFs are discussed with respect to the urgent demands in enhancing their performance, which propose a broader vision of HOFs in developing novel functional porous materials.

Chiral hybrid metal halides have been widely studied in the field of photondetectors, chiral optics, and spintronics due to their great structural flexibility and suitable bandgaps. Inspired by such great progress made in the abovementioned fields, continuous efforts need to be paid to seek other interesting applications for chiral hybrid metal halides. Herein, the synthesis of a pair of one‐dimensional enantiomorphic hybrid metal halide piezoelectrics, R/SMPCdCl4(R/SMP = R/S‐2‐methylpiperazine), and their applications in piezoelectric energy harvesting and sensing are reported. Density functional theory calculations show that these chiral piezoeletrics possess low elastic properties and high piezoelectric constants (16.71, 8.39, and 7.35 pC N−1). In addition, devices made of RMPCdCl4/PDMS (PDMS = polydimethylsiloxane) composite films are fabricated for piezoelectric energy harvesting and sensing. The piezoelectric energy harvesters with optimized content of 15 wt% RMPCdCl4/PDMS show not only excellent performance with an open‐circuit voltage of 2.57 V, short‐circuit current of 0.37 μA, and power density of 0.55 μW cm−2 but also outstanding stability of more than 3500 cycles. Meanwhile, these piezoelectric energy harvesters exhibit prominent sensing properties for detecting tapping, finger bending, walking, and running. It is demonstrated that chiral hybrid metal halides hold great potential in intelligent wearable and sensing devices.

Coordination polymers are normally considered to be brittle due to the dominance of directional coordination bonding. Here the authors report the plastic bending in a semiconducting coordination polymer crystal enabled by delamination.

The performance of adsorbents for perfluorooctanoic acid (PFOA) removal often suffers from long equilibrium times, weak binding affinities and poor stability. Here the authors report a highly efficient PFOA adsorbents by functionalizing porous organic polymers with electrostatic and hydrophobic binding sites.

Polarized neutron diffraction is used to study in depth the magnetic properties of the heterometallic compound [NH2(CH3)2][FeIIIFeII(HCOO)6] and give insight into its magnetic behaviour, addressing open questions that will contribute to a better understanding of this attention-grabbing material and other related ones. Previous results revealed that upon cooling, the magnetic moments of the FeII and FeIII sites do not order simultaneously: the magnetization of the FeII site increases faster than that of the FeIII sites. Unpolarized neutron diffraction measurements at 2 K with no external field revealed some discrepancies in the saturation value of the magnetic signal on the FeIII sites and in the ferromagnetic moment along the c axis. These discrepancies could be related to the actual distribution of magnetic moment, since unpolarized neutron diffraction gives information on the magnetic moment localized only on the magnetic ions. Polarized neutron diffraction allows an analysis of the magnitude of the spin density over magnetic and non-magnetic ions (the organic ligand and the counterion), which can give a clue to explain the low saturation on the FeIII sites and the correlation with the physical measurements. The present study also contributes to the understanding of the magneto-electric behaviour of this compound, giving insight into the role of metal disorder in the origin of the structural phase transition, which is responsible for its antiferrolelectric order, and into the influence of spin-density delocalization on its magneto-electric properties, allowing a discussion of the alternative explanations given so far for its electric properties at low temperature.

Abstract Aggregation‐induced emission (AIE) is a vital photophysical phenomenon that the luminogens in the concentrated or aggregated cases will engender the dramatically boosted emission in comparison with the dispersive states. Given this extraordinary emitting capacity exactly resolves the aggregation‐caused quenching (ACQ) situations residing in the traditional luminophores, the booming AIE luminogens have drawn tremendous interest owing to their advanced performances and colossal potential applications in various areas. Further exploitations of AIE molecules also drive the research interests in the midst of these AIE materials toward the nonlinear optical (NLO) regime. The combination of AIE and NLO effects have nurtured some unforeseen properties of AIE materials and extended their application spheres. Therefore, some NLO‐active AIE materials have been wielded in many crucial applications, for example, optical limiting, laser, bioimaging, and photodynamic therapy. Meanwhile, the impacts of aggregate on the NLO effect also deserve deep considerations and pursuits, and the modifications of aggregates promise an easy, efficient, and prompt avenue to tune the NLO properties of materials. The recent achievements and progress in the NLO properties of AIE materials have been summarized in this review. The second‐order and third‐order NLOs of the AIE materials have been introduced and their correlative applications have been discussed.

Abstract As one type of promising inorganic–organic hybrid crystal material, metal‐organic frameworks (MOFs) have attracted widespread attention in many potential fields, particularly in energy storage and conversion. Recently, effective strategies have been developed to construct uniform nanoscale MOFs (NMOFs), which not only retain inherent advantages of MOFs but also develop some improved superiorities, including shorter diffusion pathway for guest transportation and more accessible active sites for surface adsorption and reaction. Additonally, their nanometer size provides more opportunity for post‐functionalization and hybridization. In this review, recent progress on the preparation of NMOFs is summarized, primarily through bottom‐up strategies including reaction parameter‐ and coordination‐assisted synthesis, and top‐down strategies such as liquid exfoliation and salt‐template confinement. Additionally, recent applications of NMOFs in batteries as electrodes, separators, and electrolytes is discussed. Finally, some important issues concerning the fabrication and application are emphasized, which should be paid attention in future.

Stimulus-responsive metal-organic frameworks (MOFs) can be used for designing smart materials. Herein, we report a family of rationally designed MOFs which exhibit photoresponsive chiroptical and magnetic properties at room temperature. In this design, two specific nonphotochromic ligands are selected to construct enantiomeric MOFs, {Cu2(L-mal)2(bpy)2(H2O)·3H2O}n (1) and {Cu2(D-mal)2(bpy)2(H2O)·3H2O}n (2) (mal=malate, bpy=4,4’−bipyridine), which can alter their color, magnetism, and chiroptics concurrently in response to light. Upon UV or visible light irradiation, long-lived bpy− radicals are generated via photoinduced electron transfer (PET) from oxygen atoms of carboxylates and hydroxyl of malates to bpy ligands, giving rise to a 23.7% increase of magnetic susceptibility at room temperature. The participation of the chromophores (-OH and -COO−) bound with the chiral carbon during the electron transfer process results in a small dipolar transition; thus, the Cotton effects of the enantiomers are weakened along with a photoinduced color change. This work demonstrates that the simultaneous responses of chirality, optics, and magnetism can be achieved in a single compound at room temperature and may open up a new pathway for designing chiral stimuli-responsive materials.

Metal-organic frameworks (MOFs) have attracted significant attention in the past two decades due to their diverse physical properties and associated functionalities. Although numerous advances have been made, the acoustic properties of MOFs have attracted very little attention. Here, we systematically investigate the acoustic velocities and impedances of 19 prototypical MOFs via first-principle calculations. Our results demonstrate that these MOFs exhibit a wider range of acoustic velocities, higher anisotropy, and lower acoustic impedances than their inorganic counterparts, which are ascribed to their structural diversity and anisotropy, as well as low densities. In addition, the piezoelectric properties, which are intimately related to the acoustic properties, were calculated for 3 MOFs via density functional perturbation theory, which reveals that MOFs can exhibit significant piezoelectricity due to the ionic contribution. Our work provides a comprehensive study of the fundamental acoustic properties of MOFs, which could stimulate further interest in this new exciting field.

Low-dimensional metal halide perovskites (MHPs) have received much attention due to their striking semiconducting properties tunable at a molecular level, which hold great potential in the development of next-generation optoelectronic devices. However, the insufficient understanding of their stimulus-responsiveness and elastic properties hinders future practical applications. Here, the thermally responsive emissions and elastic properties of one-dimensional lead halide perovskites R- and S-MBAPbBr3 (MBA+ = methylbenzylamine) were systematically investigated via temperature-dependent photoluminescence (PL) experiments and first-principles calculations. The PL peak positions of both perovskites were redshifted by about 20 nm, and the corresponding full width at half maximum was reduced by about 40 nm, from ambient temperature to about 150 K. This kind of temperature-responsive self-trapped exciton emission could be attributed to the synergistic effect of electron–phonon coupling and thermal expansion due to the alteration of hydrogen bonding. Moreover, the elastic properties of S-MBAPbBr3 were calculated using density functional theory, revealing that its Young’s and shear moduli are in the range of 6.5–33.2 and 2.8–19.5 GPa, respectively, even smaller than those of two-dimensional MHPs. Our work demonstrates that the temperature-responsive emissions and low elastic moduli of these 1D MHPs could find use in flexible devices.

A 3D metal–organic framework [NH2(CH3)2][Cd6(L)4(DMF)6(HCOO)](DMF = N,N-dimethylformamide) (1) has been synthesized using a tripodal ligand H3L (2,4,6-tris[1-(3-carboxylphenoxy)ylmethyl]mesitylene). The obtained complex exhibits a 3D framework containing hexanuclear {Cd6} building units formed by two trinuclear {Cd3} clusters that are connected via HCOO− anions. For complex 1, the participation of the fluorescent ligand H3L not only gives rise to a strong photoluminescence emission as expected, but more interestingly, that ligand originated characteristic band could be quenched selectively by nitrobenzene with a low detection limit, showing its potential as a highly sensitive and selective sensor for nitrobenzene. Based on an electron transfer quenching mechanism, the fluorescence sensing ability of 1 is also applicable for other electron-deficient nitroaromatic compounds with high selectivity and sensitivity, i.e., 1,4-dinitrobenzene, 1,3-dinitrobenzene, 2,4-dinitrotoluene, and 4-nitrotoluene, suggesting 1 a promising fluorescence sensor for detecting and recognizing the same kind of chemicals.

Metalation of metal–organic frameworks (MOFs) has been developed as a prominent strategy for materials functionalization for pore chemistry modulation and property optimization. By introducing exotic metal ions/complexes/nanoparticles onto/into the parent framework, many metallized MOFs have exhibited significantly improved performance in a wide range of applications. In this review, we focus on the research progress in the metalation of metal–organic frameworks during the last five years, spanning the design principles, synthetic strategies, and potential applications. Based on the crystal engineering principles, a minor change in the MOF composition through metalation would lead to leveraged variation of properties. This review starts from the general strategies established for the incorporation of metal species within MOFs, followed by the design principles to graft the desired functionality while maintaining the porosity of frameworks. Facile metalation has contributed a great number of bespoke materials with excellent performance, and we summarize their applications in gas adsorption and separation, heterogeneous catalysis, detection and sensing, and energy storage and conversion. The underlying mechanisms are also investigated by state-of-the-art techniques and analyzed for gaining insight into the structure– property relationships, which would in turn facilitate the further development of design principles. Finally, the current challenges and opportunities in MOF metalation have been discussed, and the promising future directions for customizing the next-generation advanced materials have been outlined as well. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous zinc-ion batteries (ZIBs) are highly promising energy storage devices due to their advantages of high energy density, low cost, environmental friendliness, and excellent safety. Investigation of advanced cathode materials featuring high capacity is desired for their applications in high-capacity ZIBs. In this study, a porous N-doped carbon-coated manganese oxide/zinc manganate (MZM@N-C) composite was successfully prepared as an advanced cathode material for aqueous ZIBs. The MZM@N-C cathode demonstrated a superior specific capacity of 772.8 mA h g-1 at 50 mA g-1 and maintained a high specific capacity of 205 mA h g-1 after 300 cycles at a high current density of 500 mA g-1. As compared to the unmodified MnOx cathode, MZM@N-C has a higher reversible capacity and cycling stability which could be assigned to the robust one-dimensional (1D) structure and the synergistic effect of MZM@N-C, providing instructive insight into the design of high-capacity manganese-based cathodes for rechargeable aqueous ZIBs. Furthermore, a soft-pack battery was assembled using the MZM@N-C cathode, demonstrating its potential applications in various devices. [ABSTRACT FROM AUTHOR]