Precise regulation of metal cluster structures and luminescent properties is critical for the advancement of their practical applications. Copper clusters have garnered extensive attention due to their abundant, inexpensive, and excellent luminescent properties. However, their strong metallophilic interactions often restrict emissions to the red region, making it challenging to controllably tune their emission range-especially toward high-energy bands. In this work, we propose a counterion-induced strategy to modulate the structure and luminescence properties of copper clusters. By adjusting the size of counter cations, we induced varying degrees of distortion in Cu5 anionic cluster structures and directed their crystallization into distinct assembly patterns, successfully obtaining four cluster-based luminescent materials. Theoretical calculations reveal that under the steric effects of counter cations, the four Cu5 clusters exhibit different molecular configurations and intercluster interaction strengths, enabling broad-range emission wavelength modulation (546 -> 687 nm). Notably, Cu 5 -Pr-a and Cu 5 -Et demonstrate unconventional high-energy emissions. This study provides a novel approach and experimental reference for the precise control of metal cluster structures and luminescent properties.

Metal-organic chalcogenolates (MOCs), as an emerging type of hybrid semiconductor material, have garnered significant research interest owing to their tunable structures and excellent optoelectronic properties. A deep understanding of the intrinsic relationships between their structure and properties is of vital importance for controlling and optimizing their application. In this work, we obtained a 1D silver aliphatic thiolate MOC semiconductor {Ag4[(CH3)2CHS]4}∞ and studied its optical property variations induced by hydrostatic pressure. An obvious dual emission in the compound could be observed during compression, which was aroused by the closer argentophilic interaction. Multiple in situ high-pressure characterizations combined with theoretical calculations were performed to investigate the evolution of its optical properties with structures. This study presents an interesting photophysical process of dual emission evolution, enriching the research on high-pressure applications in the field of metal-organic chalcogenolates (MOCs) and providing a reference for the design of next-generation MOCs with tailored optoelectronic functions.

Metal-organic chalcogenolate is one of the excellent hybrid semiconductors; however, reports on their precise structures remain limited due to their large structural periodicity. Understanding the relationship between their structure and optical properties remains a significant challenge. External pressure is recognized as a clean and effective method for tuning the structure and properties of optical materials. In this study, we obtained a three-dimensional silver chalcogenolate, {Ag10[(CH3)2CHS]8(CN)2}n, which exhibited bright orange-red emission upon ultraviolet excitation at atmospheric pressure. Notably, this compound showed a unique piezoresponse to varying pressures. During compression, the emission centers experienced a blue shift of nearly 130 nm, followed by a red shift. Both mechanical stress and phase conversion contributed to this complex piezochromic behavior. In situ high-pressure X-ray diffraction measurements and Raman spectroscopy confirmed phase transitions during the color change. Density functional theory simulations further verified the direct band gap semiconductor characteristics of this compound and revealed how atomic contributions influenced the band structure. This work not only sheds light on the structural and optical responses to hydrostatic pressure but also explores their interrelationship in this 3D silver chalcogenolate, offering a new perspective on studying the nature of metal-organic framework semiconductors.

Brilliant blue (BB), a synthetic dye commonly used as a food coloring agent and in pharmaceutical formulations, poses significant health risks when consumed excessively. Prolonged or high intake of BB has been linked to potential toxicity, including disruptions in metabolic pathways and adverse effects on organ function, particularly the liver. In this study, a stable dual-emission sensor, consisting of carbon dots and copper nanoclusters, was designed for the highly selective detection of BB, utilizing the inner filter effect. When excited at 380 nm, this sensor displays distinct emission peaks at 430 nm and 640 nm. Upon addition of BB, the emission at 640 nm is significantly quenched, and the fluorescence intensity ratio (F640/F430) displays a linear relationship with BB concentrations ranging from 1 to 1000 nmol/L, with a detection limit of 1 nmol/L. The probe was successfully applied for detecting BB in real samples, with recoveries ranging from 94.8 % to 108.8 % and a relative standard deviation of less than 2.2 %.

It remains a big challenge to develop solid-state stimuli-responsive materials for time-dependent information encryption and inkless erasable printing with long retention times. Herein, a 2D Cu2I2-based MOF with photoresponsive spiropyran (SP) groups orderly installed on its skeleton is developed. The structural isomerization from SP to colored merocyanine (MC) form can be triggered by removing the CH3CN guests. Besides, the degree of structural isomerization and the retention time can be adjusted by controlling the amount of CH3CN guests, exhibiting dynamic photochromic behavior with multicolor states and tunable retention time. Based on these advantages, time-dependent information encryption is successfully achieved. Furthermore, the long retention time (>72 h) of the MC form under daylight conditions in the CH3CN-removed Cu2I2-based MOF and good repeatability make it promising in various applications, such as temporary calendars, price-cards, billboards, and reusable identity cards. This work provides a novel design strategy to fabricate multi-functional MOF-based smart materials for challenging applications of time-dependent information encryption and inkless erasable printing.

Circularly polarized luminescence (CPL) materials have attracted considerable attention for their promising applications in encryption, chiral sensing, and three-dimensional (3D) displays. However, the preparation of high-efficiency, pure blue CPL materials remains challenging. In this study, we reported an enantiomeric pair of triangle copper(I) clusters (R/S-Cu3) rigidified by employing chiral N-heterocyclic carbene (NHC) ligands with two pyridine-functionalized wingtips. These chiral clusters emitted pure blue phosphorescence that overlapped with that of the commercial blue phosphor having Commission Internationale de l'Eclairage (CIE) chromaticity coordinates of (0.14, 0.10), and the films exhibited an unprecedented photoluminescence quantum yield (PLQY) of ∼70.0%. Additionally, the solutions showed very bright circularly polarized phosphorescence (CPP) with a dissymmetry factor of ±2.1 × 10-3. The excellent solubility and photostability endowed these pure-blue-emitting chiral clusters with promising applications as pure blue CPP inks for 3D printing white objects, such as precise-atomic-enlarged models of metal clusters and a lovely white stereoscopic "rabbit". The intricate mechanism underlying blue phosphorescence in this small cluster and across various states is elucidated through a comprehensive approach that integrates thorough analysis of luminescence properties, controlled experiments, and theoretical calculations. For the first time, we propose that the dominant high-energy emission center is constituted by delocalized hybrid orbitals over multiple atomic centers, encompassing both the metal and the coordinated atoms. This challenges stereotypical assumptions that the cluster center solely supports low-energy emissions. This work expands the currently limited range of CPP functional materials and provides a new direction for CPP applications involving NHC-stabilized metal clusters.

Primary explosive, as a reliable initiator for secondary explosives, is the central component of micro-initiators for modern aerospace systems and military operations. However, they are typically prepared as powders, posing potential safety risks because of the inevitable particles scattering issues in the actual working environments. Here, the fabrication of a highly adaptive bulk material of copper azide (CA)-based safe primary explosive for micro-initiators is demonstrated. This bulk material, as derived by a complete azidation reaction of the carbonized metal-organic framework/cross-linked polymer hybrid template, enables the firm embedding of active CA species in a cross-linked carbon network (denoted as CA-C). Interestingly, this CA-C bulk material demonstrates multifarious mechanical stabilities (e.g., good shock and vibration resistance, and anti-overload capacity) in the simulated working conditions. Meanwhile, the CA contents in the CA-C bulk material reached as high as 70.3%, ensuring its detonation power. As a proof of concept, CA-C bulk material assembling in a micro-detonator can efficiently detonate the secondary explosive of CL-20 under laser irradiation. This work hereby advances the fabrication of safe and powerful primary explosives for the fulfillment of safe micro-initiator in a broad range of applications in aerospace systems.

Laser initiation has attracted increasing interest owing to its extraordinary safety and high reliability. However, traditional metal complex‐based laser‐ignitable primary explosives are limited by high input laser energy and low detonation ability. In this study, an efficient laser‐ignitable primary explosive‐based copper azide is prepared by constructing core‐shell hetero‐framework Cu‐MOF@COF as the precursor. The pyrolysis of Cu‐MOF@COF hybrid material affords copper azide (CA) nanoparticle confined in a porous carbon shell, referred to CA@C Shell. The evenly coated porous carbon shell functions as light‐to‐heat conversion layer efficiently promoting the laser initiation process of inside CA. Consequently, CA@C Shell can be initiated at lower laser energy thresholds (0.80 mJ at 1064 nm). This value is significantly lower than typical laser ignitable metal complex tetraamine‐cis‐bis(5‐nitro‐2H‐tetrazolato‐N 2 )cobalt(III)perchlorate (726 mJ at 808 nm). Moreover, the CA@C Shell successfully detonates the secondary explosives CL‐20 by laser energy when it is assembled in a micro‐detonator system. This study offers a unique method for constructing high performance laser‐ignitable primary explosives for micro‐detonator applications.

Covalent organic frameworks (COFs) are appealing photocatalysts for toxic chemical degradation. Great efforts have been devoted to regulate the photocatalytic performance of COFs by tuning their organic building blocks, but the relationship between COF linkage and photochemical properties has rarely been explored. Herein, we report the synthesis and characterisation of a novel aminal-linked porphyrinic COF, namely Por-Aminal-COF. Por-Aminal-COF (0.25 mol %) showed excellent photocatalytic activity toward the detoxification of the sulfur mustard simulant with a half-life (t1/2 ) of 5 min, which is far lower than that of traditional imine-linked Por-COF (t1/2 =16 min). Transient absorption spectroscopy indicated that the aminal linkages of Por-Aminal-COF facilitated the intersystem crossing process. Thus, Por-Aminal-COF showed higher triplet-state generation efficiency compared with Por-COF, consequently promoting the activation of oxygen molecular to singlet oxygen.

A novel viologen-based multifunctional Eu-MOF integrating photochromism, photomodulated fluorescence, and electrochromic and electroluminochromic properties was investigated.

Co/Co9S8 nanoparticles encapsulated in a N, S, and O ternary-doped carbon matrix were synthesized utilizing a Co-NSOMOF as a single precursor, and they exhibited excellent bifunctional electrocatalytic activity for the OER and HER. Impressively, the water splitting cell exhibited a low cell voltage of 1.56 V at 10 mA cm-2. The high performances were attributed to the synergistic effect and the protection of multi-heteroatom doped carbon shells for active Co/Co9S8 nanoparticles.

A series of silver–chalcogenide clusters was synthesised based on CrO42−/Cr2O72− anion templates.

Metal-organic frameworks (MOFs) with light-harvesting building blocks provide an excellent platform to study energy transfer in networks with well-defined structures. Here, we report the synthesis, dissolution-recrystallization structural transformation (DRST) and the Förster resonance energy transfer (FRET) properties of a 2D microporous MOF {[Cd2(L1)3(Hdabco)2]·5DMAc·6H2O}n (Cd-MOF, 1). Complex 1 can be dissolved in water and three other products with different dimensions recrystallized from the aqueous solution under diverse reaction conditions were obtained. Due to the porosity and excellent blue luminescence properties of complex 1, we also studied the FRET process between 1 and guest dyes. Two distinct organic dye molecules viz., acridine orange (AO) and rhodamine B (RhB), are encapsulated in 1 which has honeycomb-type nanochannels, and their influence on fluorescence emission has also been studied. The microporous complex 1 in (AO + RhB)@1 serves as an energy funnel that harvests high energy excitation and channels it onto AO and then onto RhB. The steady-state fluorescence and fluorescence dynamics of emission reveal successfully the process of stepwise vectorial energy transfer. Therefore, MOFs could be a class of promising host materials to be further explored in the field of energy transfer between MOF-host and organic guests.

Tunable inorganic nodes and modifiable organic linkers enable designable functionality to come to fruition in new-type porous hybrid materials, namely metal-organic frameworks (MOFs). By using viologen-functionalized m-benzenedicarboxylate as an organic linker, a terbium-organic framework embedded with asymmetric viologen species has been constructed. The reversible photochromism from bright yellow to dark green is implemented due to the favorable spatial stack of the electron donor and acceptor. The photochromic component of the organic linkers can modulate the luminescence of the tetranuclear terbium cluster under irradiation of UV light, which is defined as photoluminescence switching behavior. The different protonation levels of uncoordinated N atoms with varying pH enable the MOF as a potential fluorescent pH sensor. Thus, multiphotofunctionality, viz. photoluminescence, photochromism as well as the derivate fluorescent response to irradiation and pH have been combined in the Tb-MOF, which is the first example in the viologen-based photochromic hybrid materials.

A novel metal–organic framework, [Zn(HL)(H2O)]·[EMI] (1), has been hydro/solvothermally synthesized in the presence of [EMI]Br ionic liquid (IL) (H4L = 2,2′,4,4′-quaterphenyl tetracarboxylic acid, EMI = 1-ethyl-3-methylimidazolium). The interesting feature of 1 is that the HL ligands connect Zn(II) ions to afford a fascinating meso-helical chains with left- and right-handed helical loops in one single strand along the c axis, which are further connected by O–H···O hydrogen bonds to generate a 3D supramolecular framework. The free IL [EMI] cations are filled in the voids of the framework. The title complex was characterized by elemental analysis, IR spectra, thermogravimetric analysis, single-crystal X-ray crystallography and powder X-ray diffraction. More interesting, the fluorescence of 1 shows fast and reversible detection of NB vapour, which exhibits its potential as NB sensor.

We report here seven metal-organic complexes, {[Zn.L)(H2O)(3)]center dot H2O}(n) (1), {[Zn(L)]center dot H2O}(n) (2), {[Zn(L)(4,4'-bpy)(0.5)]center dot 2H(2)O}(n) (3), {[Cd(L)]center dot H2O}(n) (4), {[Cd(L)(1,4-bbi)(H2O)]center dot H2O}(n) (5), {[Cu(L)(4,4'-bpy)(H2O)]center dot 5H(2)O}(n) (6), and {[Cu(L)(bpe)]center dot 6H(2)O}(n) (7), prepared by a hydrothermal method (H3L+Cl- = 4-carboxy-1-(3,5-dicarboxybenzyl)- pyridinium chloride, bpy = 4,4'-bipyridine, bbi = 1,1'-(1,4-butanediyl) bis(imidazole), bpe = 1,2-di(pyridine-4-yl)-ethylene). These complexes show different structures including helical chains, novel pillared layers, 3D 3-fold interpenetrating frameworks, interesting 2D -> 3D interdigitated architectures and Z-shaped double layer structures, and so on. The diversity of the structures of these complexes proves that the newly synthesized ligand H3L+Cl- is an excellent candidate for the construction of MOFs. Additionally, the thermal stabilities and photoluminescence properties are also investigated.

A series of novel heteronuclear/homonuclear coordination polymers {[Ag-2(bpy)(2)(H2O)][Cd(5-iipa)(2)]center dot 2H(2)O}(n) (1), {[Ag-2(phen)(2)][Cd(5-iipa)(2)]center dot H2O}(n) (2), [Ag-2(5-iipa)(bbi)(0.5)](n) (3), {[Ag(5-iipa)][Ag(bpa)]}(n) (4), [Ag-4(5-iipa)(2)(p-bix)(2)](n) (5), have been solvothermally synthesized by 5-iodo-isophthalic acid (5-iipa) and N-donor ancillary ligands, such as bpy (4,4'-bipyridine), phen (1,10-phenanthroline), bbi (1,1'-(1,4-butanediyl)bis(imidazole)), bpa (1,2-bis(4-pyridyl)ethane) and p-bix(1,4-bis(imidazol-1-ylmethyl)-benzene). Compound 1 presents a unique "host-guest" structure. The structure of compound 2 is composed of Ag(I)-Cd(II) heteronuclear metal-organic layers, such layers are extended by weak Ag center dot center dot center dot I interactions into a 3D supramolecular framework. While 3, 4 and 5 are homonuclear Ag(I) coordination polymers.

A series of six coordination polymers, namely, [Cd-1.5(L)] (1), {Cd-1.5(L)(bpp)] (2), {{Cd-1.5(L)(p-bix)]center dot H2O}(n) (3), {Cd-1.5(L)(m-bix)(n) (4), {{Cd-1.5(L)(dpa)(3)(H2O)center dot 2H(2)O}(n) (5), and {{Cd-1.5(L)(bpbd)(2.5)]center dot 2H(2)O} (6) (Na3L = (S)-(-)-5-(1-carboxy-ethoxymethyl)-isophthalic acid trisodium salt), have been hydrothermally synthesized through the reaction of Na3L with divalent cadmium salts with, or without the presence of ancillary nitrogen ligands (bpp = 1,3-bi(4-pyridyl)propane, p-bix = 1,4-bis(imidazol-1-ylmethyl)benzene, m-bix = 1,3-bis(imidazol-1-ylmethyl)benzene, dpa = 4,4'-dipyridylamine, bpbd = 2,3-bis(4'-pyridy1)-2,3-butanediol)). Complex 1 is a threedimensional (3D) framework and displays a (4,8)-connected framework with {4(12).6(12).8(4)} (flu) topology. 2 features a 3D architecture too, in which the one-dimensional (1D) (Cd-bpp), helical chains are alternately arranged in a right- and left-handed sequence. Complex 3 exhibits a homochiral 3D framework and is a new (3,8)-connected net with a Schlafli symbol of {4.5. 6}(2){4(2).5(6).6(18).7.8} topology. Complex 4 bears a homochiral layered structure, which is united together to generate a 3D supramolecular structure through interlayer C-H center dot center dot center dot O and C-H center dot center dot center dot pi interactions. Interlayer C-H center dot center dot center dot pi and N-H center dot center dot center dot N interactions led layered complex 5 to a 3D supramolecular architecture. Complex 6 shows a new (3,5,6)-connected net with a Schlafli symbol of {4.6(2)}(2){4(2). 6(10). 8(2).10}{4(2).6(6).8(2)}(2) J topology. Complexes 3 and 4 crystallize in the chiral C2 space group, and their circular dichroism spectra exhibit obvious positive or negative Cotton effects. Moreover, 3 and 4 are second-harmonic generation (SHG) active, and the SHG efficiency is 0.5 and 0.4 times as much as that of urea, respectively.

A flexible aromatic multicarboxylate ligand and Cd(II) ions assemble into a chiral multihelical porous metal-organic framework with second-order nonlinear optical and ferroelectric properties. The obtained guest-free form highly selectively senses small organic molecules and adsorbs large dye molecules.

A chiral two-dimensional (2D) coordination polymer {[Zn(cmmb)(1,4-bbi)]·H2O}n (1) has been synthesized by a hydrothermal reaction of Zn(NO3)2·6H2O with 4- (carboxymethoxy)-2-methylbenzoic acid (H2cmmb) and 1,1`-(1,4-butanediyl)bis(imidazole) (1,4-bbi). It has been characterized by elemental analysis, X-ray crystallography, IR spectroscopy and thermogravimetry, and also by its fluorescence properties. The metal-organic layer of the complex is held together with its neighbors via C-H···O hydrogen bonds to give rise to a chiral three-dimensional supramolecular network.