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The rational design of 2D polyoxometalate-based metal-organic framework (POMOF) nanosheets on a conductive substrate as a self-supporting electrode is highly attractive but a great challenge. Herein is the first demonstration of POMOF nanopillar arrays consisting of 2D nanosheets as a self-supported electrode for the hydrogen evolution reaction (HER) in acidic conditions. Single-crystal X-ray analysis reveal that our as-prepared 2D [Co

Room-temperature phosphorescence (RTP) materials have widespread applications in biological imaging, anticounterfeiting, and optoelectronic devices. Because of the predesignability of metal-organic complexes (MOCs), the RTP materials based on MOC systems have received huge attention from researchers. The coordinate anchoring of luminophores to enhance the rigidity of organic molecules and restrict the nonradiative transition offers opportunities for generating MOC materials with captivating RTP performance. Hitherto, most of the MOC-based RTP materials feature a single luminophore ligand. The development of new MOC systems with RTP functionality is still challenging. Herein, we use the mixed-ligand synthetic strategy to produce isostructural MOCs, [Zn(TIMB)(X

A new type of SBUs composed of high connected azido, particularly the rare μ1,1,1,1-N3 bridged clusters, was extended to coordination networks.

The development of new hybrid photochromic materials (HPMs) systems received huge interest of chemists because of their potentialities in many domains and feasibilities of obtaining other photomodu...

The assembly of a tetradentate pyridine-derived ligand with CuX has afforded two isostructural Cu(I)-organic frameworks [Cu

Crystalline complexes that exhibited light switchable proton conductivity are of great interest but still a challenge in material science. Herein, a terbium phosphonate chain complex was synthesized through assembly of electron-rich phosphonate units, electron-deficient polypyridine components and paramagnetic Tb3+ ions. Via light irradiation and heat treatment, the photogenerated radicals could simultaneously and reversibly tune the photochromic, luminescent and magnetic properties. Originated from the abundant hydrogen bonding networks formed between PO3 groups and lattice water molecules, proton conductive behaviour was explored with high proton conductivity of (1.74±0.19)×10−3 S cm−1 at 80 °C and 100% relative humidity. Importantly, accompanied with the colorless sample changed to blue, the proton conductivity increased about 20% after room temperature light illumination, implying that light irradiation could act as an external stimulus to enhance the conductive properties of original material. This work innovatively realized the light responsive conductive property in the electron transfer photochromic materials, providing a novel strategy for the construction of smart materials.

Using a pyridine-derived molecule 1,3,5-tris(4-pyridyl)benzene (TPB) and a polycarboxylate linker 1,3-benzenedicarboxylic acid (H2BDC), a Co(II)-based coordination polymer {[Co(TPB)(BDC)]·0.5H2O} (...

Herein, we report a dia-type metal–organic hybrid network based on the [Ag4Br6] clusters and hexamethylenetetramine molecules wherein both the inorganic nodes and organic linkers feature adamantane...

As a significant class of photochromic materials, crystalline hybrid photochromic materials (CHPMs) have attracted widespread attention of researchers because of their possibilities for generating other photoresponsive properties and advantages in understanding the underlying relationship between structure and photoresponsive performance. The predesign of suitable ligands plays a major role in generating desirable CHPMs. Hitherto, most CHPMs have been built from photodeformable or photoresponsive tectons. However, the synthesis of these ligands is usually time-consuming and expensive, and this greatly restricts their large-scale preparation and practical application. Therefore, it is necessary to explore new families of CHPMs besides the existing CHPMs. Herein, a simple and general method for constructing CHPMs by decorating metal nitrate with a coplanar bipyridine moiety, namely 1,10-phenanthroline (phen), is reported. The resulting products exhibit photocoloration in response to Xe-lamp irradiation. The electron transfer (ET) from the coplanar NO3 - species (as π-electron donors, π-EDs) to coplanar phen moieties (as π-electron acceptors, π-EAs) is responsible for the resulting photochromism. The influence of the coordination environment and central metal ion on the photochromism was also studied. This work demonstrates that the introduction of coplanar organic tectons as π-EAs to metal nitrates as π-EDs with the collaboration of ET and coordination-assembly strategies is a simple and general method to manufacture CHPMs.

As a kind of metastable aggregation between iron ions and iron hydroxide precipitates, Fe clusters can only be isolated under narrow synthesis conditions. Here, two Fe clusters with different structural models, [Fe6(H2thmmg)6] (Fe6) and [Fe18O8(OH)8(H2thmmg)10] (Fe18), are constructed based on a rare N-tris(hydroxymethyl)methylglycine (H5thmmg) ligand. The cyclic Fe6 can be visualized as a “six-vane windmill” comprised of 6 Fe3+ and 6 H2thmmg3− ligands. Unlike the cyclic configuration of Fe6, the Fe18 cluster features a bricky structure like a “Chinese knot” coordinated by three species, H2thmmg3−, OH− and O2−. It was obtained by adding more triethylamine to the reactive solution of Fe6 which yielded more coordinated species OH− and O2−. Moreover, the conversion from Fe6 to Fe18 was successfully achieved by adding more triethylamine, realizing nuclearity enlargement and structural regulation of Fe clusters. Furthermore, the magnetic properties of Fe6 and Fe18 exhibit antiferromagnetism. This work reports two novel alkali-regulated Fe clusters and further realizes the transformation of nuclearity and structure, which provides some reference for the structural predesign and adjustment of metal nanoclusters.

By employing a triazole–pyridine-containing ligand, two novel coordination polymers with Ag(I) clusters exhibiting different architectures have been successfully constructed. Structural analysis indicates that diverse coordination modes of the N-donor linker are responsible for the network difference for these two compounds, affording an isolated cluster for 1 and a 2D framework for 2, respectively. Compound 1 features a butterfly-shaped [Ag8(bptp)4(H2O)2] cluster wherein strong argentophilic interactions could be observed. The linkage of Ag(I) with N and I centers gives rise to a tetranuclear building unit [Ag4(bptp)3I] in 2, which is further extended to a 2D network with the assistance of the N-donor linkers. The syntheses and crystal structures have been investigated. Solid-state photoluminescence emissions as well as luminescence lifetimes of 1 and 2 have also been studied. Moreover, temperature-dependent luminescence tests show that an excellent linear relationship between temperature and emission intensity in the ranges of 77–298 K and 77–200 K could be observed for compounds 1 and 2, respectively. The wide temperature sensing range especially for 1 implies that they could act as promising ratiometric fluorescence molecular thermometers.

Hybrid photochromic materias (HPMs), especially crystalline HPMs (CHPMs), have been widely investigated due to their feasibility in maintaining the advantages of each constituent and genearating captivating photomodulated functionality. Metal-organic complexes (MOCs), as promising candidates for fabricating CHPMs, have attracted the interest of researchers. The molecular predesign of ligands plays a crucial role in yielding MOC-based CHPMs with tunable photochromic functionality. Hitherto, a great majority of CHPMs are driven by photosensitive ligands. However, the complicated synthesis and high cost of photosensitive ligands obviously prevent the macro-synthesis and future application of these CHPMs. Thus, it is indispensable to explore novel branches of CHPMs. Herein, we report a series of photochromic solid materials bearing modulated photochromic properties by hybridizing metal chlorides with a nonphotosensitive coplanar dipyridine unit 1,10-phenanthroline (phen) and its derivative 5-chloro-1,10-phenanthroline (5-Cl-phen). The resulting hybrids, [ZnCl2(phen)] (1), [CdCl2(phen)] (2), [PbCl2(phen)] (3), [ZnCl(H2O)(5-Cl-phen)2]Cl·2H2O (4), [Cd2Cl4(5-Cl-phen)2] (5) and [Pb2Cl4(5-Cl-phen)2] (6), exhibit distinct structures from the isolated molecular complexes (1 and 4) to the hybrid chain (2, 3, 5 and 6) because of the distinct coordination mode of central metal ions and chloride ions. After photo-irradiation with a Xe-lamp, all complexes, as expected, exhibited apparent color change because of the photoinduced electron transfer (ET) between coordinated chloride ions (Cl-) as electron donors (EDs) and the coordinated coplanar phen and 5-Cl-phen species as electron acceptors (EAs). More importantly, the photochromic performance of the title complexes could be modulated by phen and 5-Cl-phen. This study provides a general and facile way for modulating the structure and photochromic performance of hybrid metal chlorides with phen or phen-based derivatives under the synergy of crystalline engineering strategy and ET mechanism.

By virtue of the template synthesis strategy, a series of haloargentates [Me-hmta][AgI2]·H2O (1), [Me-hmta][Ag2I3] (2) and [Me-hmta][Ag2Br3] (3) (hmta = hexamethylenetetramine), have been successfully prepared. Compounds 1–3 feature diverse infinite chains with in situ methylated Me-hmta cations serving as the templates and structure-directing agents. The syntheses, crystal structures and characterizations have been investigated for the compounds. Interestingly, compounds 1 and 2 exhibit the reversible photo-induced chromic behaviors. The solid samples can be colored with light illumination and further decolored in the presence of heat. Moreover, photocatalysis tests have been performed on 2 and 3, which display that the compounds can be considered as promising photocatalysts with high efficiency toward the degradation of organic dye pollutants.

The combination of a conjugated coplanar dipyridine moiety 1,10-phenanthroline (1,10-phen) with a metal carboxylate system produces two isostructural supramolecular chains [M(HBTA)(1,10-phen)2] (M = Zn for 1, M = Cd for 2) (H3BTA = benzene-1,2,3-tricarboxylic acid). Both 1 and 2 feature monomeric units as molecular building blocks (MBBs), which further connect with each other to form a supramolecular chain via forming hydrogen bonds with adjacent units. The coordinate linkage of 1,10-phen as π-electron acceptors (π-EAs) and tricarboxylate as electron donors (EDs) results in the electron transfer (ET)-induced photochromic functionality of 1 and 2 in response to Xe-lamp irradiation under ambient conditions. Distinct from the plenty of previous photochromic compounds derived from photosensitive moieties such as pyridinium-derivatives and photodeformable molecules, the photochromism in 1 and 2 is driven by the photoinduced ET between tricarboxylate and non-photochromic 1,10-phen units. Because of the coplanar characteristics of 1,10-phen, the photoactivated samples feature good stability under ambient conditions. More importantly, the resulting photochromism of isostructural 1 and 2 could be modulated by the category of metal ions, which is totally different from the previous works with focus on the design of organic ligands. Considering the great varieties of carboxylate ligands, this work offers a general method for the construction of photochromic complexes via integrating coplanar 1,10-phen units with metal-carboxylate systems under the guidance of the ET mechanism and MBB assembly strategy and modulating the photochromism of the resultant isostructural products via tuning the category of metal ions.

Hybrid photochromic materials (HPMs) with specific photoresponsive functionality have applications in many fields. The photoinduced electron-transfer (ET) strategy has been proved to be effective in the synthesis of HPMs with diverse photomodulated properties. The exploitation of new electron acceptors (EAs) is meaningful for promoting the development of HPMs. In this work, we introduced a rigid tetraimidazole derivative, 3,3,5,5-tetra(imidazol-1-yl)-1,1-biphenyl (TIBP) as a potential EA, into a metal-diphosphonate (1-hydroxyethylidene-1,1-diphosphonic acid, H

Metal–organic frameworks (MOFs), as an emerging hybrid material, have been well explored in numerous areas such as adsorption, separation, catalysis, magnetism, photoluminescence, etc. Recently, th...

Room-temperature phosphorescence (RTP) materials have potential applications in anticounterfeiting, biochemistry, and optical recording. It is significant to develop a novel approach to enriching RTP materials. Here two new hybrid RTP solids were obtained by the introduction of organic 1,3,5-tris(1-imidazolyl)benzene and halogen atoms to simultaneously coordinate with inorganic moieties. Single-crystal X-ray analysis reveals that Br atoms are oriented toward the adjacent organic molecules that can play an important heavy-atom effect (HAE). Notably, such a HAE realized by orienting the Br atom to the location immediately adjacent to the triplets produced can efficiently facilitate intersystem crossing and results in RTP with intensity similar to that of the fluorescence in steady-state photoluminescence.

Guided by diverse solvated metal cations, three novel iodoargentates with various architectures ranging from a one-dimensional chain to a two-dimensional layered-network have been successfully cons...

Grafting conjugated dipyridine derivatives, BPB (1,4-bis(pyrid-4-yl)benzene) and BPBP (4,4'-di(pyridin-4-yl)-1,1'-biphenyl), to a metal phosphite system yields two hybrid zincophosphites [Zn2(HPO3)2(BPB)]·0.5DMF (1, DMF = N,N-dimethylformamide) and [H2BPBP]3·[Zn5Cl8(HPO3)4]·2H2O (2). 1 shows a hybrid layer with the inorganic zincophosphite chains as building blocks. 2 shows isolated pentanuclear Zn clusters in which four phosphite moieties as a bridging ligand, together with eight chloride ions as terminal ligands, bond with five Zn ions to produce anionic inorganic clusters. The negative charge was compensated by the protonated dipyridine derivative species, which was located in the intercluster voids and interplays with the adjacent clusters via N-HO-P hydrogen bonds. Interestingly, 1 and 2 show photochromism driven by the coordinate bond- and hydrogen bond-assisted electron transfer (ET) under the stimulus of Xe lamp irradiation in ambient conditions. Although 1 and 2 had similar constituents in terms of electron donors (EDs) and electron acceptors (EAs), they exhibited distinct photochromic mechanism with ligand-to-ligand ET (LLET) for 1 and proton-coupled ET (PCET) for 2. Unlike the majority of previous hybrid photochromic materials supported by photo-responsive species, the photochromism in 1 and 2 was based on the ET between phosphite and non-photochromic dipyridine derivative units. Our work provides a general strategy towards the design of photochromic hybrid phosphites by integrating conjugated dipyridine- or polypyridine derivative units with metal phosphites.

Hybrid photochromic materials (HPMs) have potential applications in numerous fields, such as display, protection, and information storage. The generation of HPMs with tunable photochromic performance is meaningful for the availability of smart photoresponsive materials. As a good platform, crystalline HPMs (CHPMs) provide possibilities to generate desirable products because of their synthetic tunability. To achieve this goal, how to introduce predesigned organic ligands as electron acceptors (EAs) into suitable electron donor (ED) systems is significant for yielding products with hybrid ED-EA structure triggering electron transfer (ET) after photo-stimulus. In this study, inserting protonated 1,10-phenanthroline (phen) (as EAs) and its monosubstituted derivatives 5-Cl-phen and 5-NH

Zero-dimensional cluster complexes and coordination polymers for magnetic refrigeration have attracted great interest in the last decade. In-situ synthesis is a widely-used method to assemble various molecular magnetorefrigerant materials derived from different types of ligands. This review focuses mainly on the synthesis, structure and magnetochemistry of molecular magnetorefrigerant materials via in-situ synthesis, with an emphasis on in-situ generation of ligands, metal ions and templates. The first section gives a brief discussion on molecular magnetorefrigerants and some important principles obtained from magneto–structural correlation. The in-situ synthetic strategy will also be referred to and elucidated in this part. The next three sections give overviews of the main results obtained by our group and other groups in recent years, which are, in-situ generated ligands, metal ions and templates in the synthesis of molecular magnetorefrigerant materials. Finally, the conclusions and perspectives of molecular magnetorefrigerant materials will be presented. Some of the trends could provide new insights for the further development of this promising area.

Room-temperature phosphorescence (RTP) materials have gained much attention, because of their applications in chemical sensing, optoelectronics, and security systems. Transition-metal complexes, particularly those of IrIII, PtII, RuII, and AuI, have preciously been investigated in the quest for excellent RTP materials. Recently, the pure organic molecules caught the eyes of researchers. Although great achievement has been reached, expanding the available types of RTP materials and hunting for top-performing RTP materials are still significant to promote the development of RTP materials. In this work, we report a series of isostructural hybrid zincophosphite [Zn3(HPO3)2(tib)2]X2 (X- = Cl-, Br-, I-; tib = 1,3,5-tris(1-imidazolyl)-benzene), which feature a cationic host structure and an anionic guest (X-). Because of the restriction of molecular vibrations/rotations of organic luminogens (tib) and the heavy-atom effect of the guest halide ion (X-), the title compounds exhibit almost pure RTP with absolute phosphorescence quantum yields of 5.8%-9.1%. More interestingly, unique excitation-energy-dependent phosphorescence has been observed in these hybrid materials. The phosphorescence origin has also been illustrated by theoretical calculations. Our work provides new insights into the design of RTP materials. Considering the structural diversity together with the rich host-guest chemistry of metal-phosphite/phosphate, we offer a new avenue to explore superior crystalline RTP materials.

A 2D anionic Cd-based coordination host was constructed from the linkage of the metal ions and 6-sulfonicotinic acid (SNA, in situ generated from the breaking of disulfide bond in 6,6’-dithiodinicotinic acid) whose interior spaces are occupied with cationic [(CH3)2NH2]+ guests. The compound exhibits an interesting ion-exchange behavior for both encapsulation of lanthanide (Ln) ions and organic dye. Through the fixation of Ln3+ within the host, the designed composite can be endowed with high photoluminescence property. Moreover, the free cations could be readily substituted by methylene blue (MB), with more than 90% of MB (10−5 M) being selectively absorbed after 12 h, making the title compound to be a great medium for dye adsorption and separation.

A series of s mediated by a long and flexible amine 1,2-bis(3-aminopropylamino)ethane (BAPEN), [Zn3(HEDP)2(H2BAPEN)(H2O)]·5H2O (1), (H4BAPEN)0.5·[Zn3(HEDP)2(H2O)]·2H2O (2), and (H4BAPEN)0.5·[Zn3(HEDP)2]·H2O (3) (HEDP = 1-hydroxyethylidenediphosphonate, CH3C(OH)(PO3)2), were successfully assembled, showing diverse structures with different dimensions. Compound 1 displays an infinite Zn-HEDP chain that is decorated by chelating BAPEN. Compound 2 possesses an anionic Zn-HEDP layer structure with the protonated BAPEN as a charge balancer. Compound 3 features a 3D Zn-HEDP network with protonated BAPEN as the template. The structural diversity for 1–3 from 1D to 2D and 3D was modulated by BAPEN in the assembly process (coordination role for 1 and template role for 2 and 3) together with the different reaction conditions. The photoluminescence properties of compounds 1–3 are investigated. The results show that the solids 1–3 exhibit intense blue fluorescence at ambient temperature under UV light irradiation. Mor...

Two series of lanthanide phosphonates, [H4BAPEN]1.5·[Ln2(HEDP)3]·5H2O [Ln = Gd3+ (1-Gd), Tb3+ (1-Tb), Dy3+ (1-Dy)] and [H4BAPEN]0.5·[LnLi(HHEDP)2(H2O)2]·2H2O [Ln = Gd3+ (2-Gd), Tb3+ (2-Tb), Dy3+ (2...

Solvated lanthanide (Ln) cations as templates were employed to assist the fabrication of a series of iodocuprates {[Ln(DMSO)7(CH3OH)][Cu5I7]·I}n [Ln = Eu3+ (1), Tb3+ (2), Dy3+ (3)] (DMSO = dimethyl sulfoxide) and {[Ln(DMF)8][Cu8I11]}n [Ln = Eu3+ (4), Tb3+ (5), Dy3+ (6)] (DMF = N,N-dimethylformamide). The obtained materials are equipped with good photoluminescence and magnetic properties by virtue of the functional Ln3+ ions. The synthetic strategy, structural analysis, and properties for these multifunctional materials are discussed in detail. Notably, based on 4 and 5, a Ln-doped iodocuprate {[Eu0.37Tb0.31Tm0.32(DMF)8][Cu8I11]}n (7) was successfully constructed, exhibiting white-light emission at room temperature when excited by UV light, which offers a novel strategy to obtain promising optical function materials. Moreover, the combination of Ln3+ and iodocuprates in this work provides a new way to construct multifunctional molecular materials.

The cationic [Pb4(OH)4]4+ cubane as a template was first introduced to the 3D iodocuprate network, which is fabricated from the alternative connection of infinite [Cu2I2]n chains and μ2-I linkers. Distinct from most of the photocatalysts with UV or visible light for the photocatalytic degradation of an organic pollutant, the target compound could accomplish this task under direct sunlight because of the introduction of photoactive species. Our work provides a promising strategy to generate superior photocatalysts via the encapsulation of photoactive units into open frameworks.

The coordinative linkage of supramolecular zincophosphate building units and an extended dipyridine unit, 1,4-di(pyridine-4-yl)benzene (bpyb), generates two hybrid photochromic frames. The structural and photochromic diversities were mainly attributable to the distinct coordination mode of bpyb in the resultant structure. Different from most of the reported photochromic materials driven by photochromically active units, the crystalline hybrid photochromic materials in this work are decorated by non-photochromic bpyb. The metal-assisted phosphate-to-bpyb charge transfer is responsible for the photochromism. Our work provides a new perspective to develop photochromic hybrid materials based on non-photochromic moieties.

Cryo-magnetic coolants based on the magnetocaloric effect (MCE) usually need relatively large fields to achieve practical cooling performance. Thus, it is important to hunt for molecular cryo-magnetic coolants with superior performance of the MCE under low fields (smaller than 2 T), considering the readily attainable low fields from commercialized Nd–Fe–B permanent magnets. In this work, the crystal structure, magnetic susceptibility and isothermal magnetization for two hybrid Gd-complexes, (NH4)[Gd(C2O4)(SO4)(H2O)] (1) and [Gd(C2O4)0.5(CO3)(H2O)] (2), cobridged by organic and inorganic ligands, were solvothermally synthesized and magnetically characterised, with the goal of obtaining novel molecular cryo-magnetic coolants. For 1, the sulfate bridges GdIII ions to generate inorganic chains as supramolecular building blocks (SBBs), which are further connected by the oxalate to result in the final host anionic architecture with an ammonium ion as the guest to balance the charge. For 2, the carbonate bridges GdIII ions to form inorganic layers as SBBs, which are further linked by the oxalate to give birth to the resultant pillar-layer structure. Because the merits of organic oxalate ligands and inorganic ligands (sulfate and carbonate) work together, the resultant compounds show a weak magnetic exchange interaction, a low molecular weight and a dense frame structure, and the observed maximum entropy change (−ΔSmaxm) is up to 42.4 J kg−1 K−1 for 1 at ΔH = 7 T and T = 2 K and 50.7 J kg−1 K−1 for 2 at ΔH = 7 T and T = 4 K, beyond the performance of commercialized gadolinium gallium garnet Gd3Ga5O12 (GGG, −ΔSmaxm = 38.4 J kg−1 K−1 with ΔH = 7 T). Notably, the −ΔSmaxm still reaches 25.2 J kg−1 K−1 for 1 and 26.8 J kg−1 K−1 for 2 at T = 2 K and ΔH = 2 T, and 32.3 J kg−1 K−1 for 1 and 33.3 J kg−1 K−1 for 2 at T = 2 K and ΔH = 3 T, which already outperform GGG (about 24 J kg−1 K−1 with ΔH = 3 T) and make them excellent cryo-magnetic refrigerants for low-temperature applications, even under low external fields.

Coordinative bonding of the inorganic zincophosphite layer and organic linear bipyridine unit generates two hybrid photochromic frames [Zn(HPO3)(L)0.5] (L = 4,4′-bipy for 1, 1,4-dpb for 2). Distinct from the familiar hybrid photochromic materials based on photochromically active moieties, the photochromism in the resultant crystalline hybrid materials is driven by the metal-assisted charge transfer between the phosphite and its corresponding non-photochromic bipyridine units. Interestingly, the photochromic performance of the final products could be modulated via enlarging the conjugated length of the non-photochromic bipyridine units, which provides new insight into the design of superior photochromic materials via tailoring the organic moieties of the parent compound.

A pillared-layer strategy is employed to assist the construction of two water-stable Zn-based metal–organic frameworks (MOFs) in this work, [ZnL(Bipy)]·0.5H2O (1) and [ZnL(Bpyb)]·1.5H2O (2) (H2L = 5-(pyridine-4-yl)isophthalic acid, Bipy = 4,4′-bipyridine, and Bpyb = 1,4-bis(pyrid-4-yl)benzene). The linkage of Zn centers and L2− ligands affords the layer structures, which are further pillared by the linear N-donor ligands to the three-dimensional architectures. The “pillars” with diverse molecular lengths lead to different pore sizes in 1 and 2, which show different sorption behaviors for iodine capture. Additionally, the photoluminescence properties of compounds 1 and 2 were investigated. Moreover, the photoluminescence sensing experiment indicates that compound 1 can be considered to be a promising selective sensor for Fe3+.

A series of heterometallic formate framework templated by amines were solvothermally prepared. They feature the formula of [AI][CrMII(HCO2)6] (AI = NH4H2OI and M = Mn for 1, AI = CH3NH3I and M = Fe for 2, AI = CH3NH2CH3I and M = Co for 3, AI = CH3NH3I and M = Ni for 4). The title compounds exhibit isostructural niccolite architectures with differences only in the host metal ions and guest amines. Tunable ferromagnetic (FO) strength was realized in the resulting framework under the guidance of orthogonal magnetic orbital analysis of CrIII (t2g3eg) and MII (t2g3eg2 for MnII, t2g4eg2 for FeII, t2g5eg2 for CoII, t2g6eg2 for NiII) ions. The magnetic ordering temperatures derived from the experimental magnetic measurements for 1–4 are lower than 2, 10.3, 7.6, and 22.0 K, respectively. Notably, thanks to the weak FO coupling between CrIII and MnII ions, compound 1 displays a large magnetocaloric effect bearing the maximum of magnetic entropy change (−ΔSmmax) up to 43.9 J kg–1 K–1 with ΔH = 7 T and T = 3.5 K, lar...

Herein, we report a

As promising photoresponsive materials and potential smart materials, hybrid photochromic materials (HPMs), especially for crystalline HPMs (CHPMs), have been broadly explored for their potential in inheriting the merits of each constituents, and intriguing photomodulated functionality. Hitherto, the photoresponsive functionality in explored CHPMs mainly concentrate on dyad combination. By contrast, triple or quadruple photoresponsive properties are very rare because of the limited compatibility of multiple photoresponsive functionality in a single system. In this work, the electron-transfer (ET) and crystal engineering strategies were utilized to predesign CHPMs with multiple photoresponsive properties via the collaboration of paramagnetic metal ion (Dy3+ ), electron-donor (ED) ligand (benzene-1,2,3-tricarboxylic acid, H3 BTA) and electron-acceptor (EA) ligand (1,10-phenanthroline, phen). The resulting complex [Dy(BTA)(phen)2 ]⋅2H2 O (1) shows hybrid chain with the intrachain Dy3+ ions bridged and chelated by tricarboxylate and phen ligands, respectively. After photostimuli, the ET between tricarboxylate and phen results in photogenerated radicals and the resultant quadruple photoresponsive properties. Considering the abundant resources of paramagnetic metal ions, ED- and EA-ligands, this work provides a general method to construct CHPMs with multiple photoresponsive performances via the collaboration of each unit under the guidance of ET and crystal engineering strategies.

Tunable full-color room temperature phosphorescence (RTP) is charming due to its potentials in multiple anti-counterfeitings, all-color displays, and multichannel biomarkers. However, it is a huge challenge to acquire excitation-dependent continuously adjustable full-color RTP from a single-component compound. Herein, we report two Zn(II)−based organic complexes, which are the first examples that present blue, cyan, green, yellow, orange, and red continuously tunable phosphorescence with decent quantum efficiency in response to variation of excitation energy at ambient conditions. The unique photoluminescence property is induced by multiple triplet decay pathways, i.e. 3ligand-centered* and 3charge transfer*. The population and stabilization of the triplet excitons benefit from heavy atom effect of Br ions and restriction of molecular motion due to crystallization. This work contributes an insight for the construction of full-color RTP materials and endows Zn(II)−based organic complexes with fresh features for extensive applications.

The intermarriage of neutral and tripodal imidazole ligand, tris(4-(1H-imidazol-1-yl)phenyl)amine (TIPA), with zinc phosphite yields two hybrid phosphites, [Zn2 (HPO3 )2 (TIPA)]⋅2 H2 O (1) and [Zn3 (HPO3 )3 (TIPA)]⋅6 H2 O (2). Compound 1 has a hybrid sheet with neutral zinc-phosphite chains as supramolecular building blocks (SBBs), whereas 2 exhibits a 3D hybrid architecture with other neutral zincophosphite chains as supramolecular building blocks. The structural discrepancy between 1 and 2 is mainly due to the distinct linkage modes between organic TIPA ligands and inorganic zincophosphite chains. Interestingly, compounds 1 and 2 feature fast photochromism in response to UV light irradiation under ambient conditions. The discrepancy of photochromic performance between 1 and 2 is mainly due to the different geometrical configuration of the TIPA ligand. Different to majority of reported hybrid photochromic compounds driven by photochromic active units, the photochromism in 1 and 2 is derived from the electron transfer (ET) between phosphite and non-photochromic triimidazole-derivative ligand TIPA. Compared with the widely explored nonphotochromic polypyridine-derivative as electron acceptors (EAs), our work provides a new EA model for the design of hybrid photochromic materials based on the ligand-to-ligand ET mechanism. A multiple anti-counterfeiting application based on 1 and 2 was investigated.

Exploitation of room temperature (RT) photochromism and photomagnetism to induce single-molecule magnet (SMM) behavior has potential applications toward optical switches and magnetic memories, and remains a tremendous challenge in the development of new bulk magnets. Herein, a series of chain complexes [Ln3(H-HEDP)3(H2-HEDP)3]·2H3-TPT·H4-HEDP·10H2O (QDU-1; Ln = Dy (QDU-1(Dy)), Gd (QDU-1(Gd)), and Y (QDU-1(Y)); HEDP = hydroxyethylidene diphosphonate; TPT = 2,4,6-tri(4-pyridyl)-1,3,5-triazine) were synthesized by solvothermal reactions. All the compounds exhibited reversible photochromic and photomagnetic behaviors via UV light irradiation at RT, induced by the photogenerated radicals via a photoinduced electron transfer (PET) mechanism. More importantly, the PET process induced significant variations in magnetic interactions for the Dy(III) congener. Strong ferromagnetic coupling with remarkably slow magnetic relaxation without applied dc fields was observed between DyIII ions and photogenerated O• radicals, showing SMM behavior after RT illumination. For the first time, we observed the reversible RT photochromism and photomagnetism in the lanthanide-based materials. This work realized the radicals-actuated on/off SMM behavior via RT light irradiation, providing a new strategy for constructing the light-induced SMMs.

Photochromic materials have broad application prospects in the fields of molecular switching, detection, biological, and molecular machines. Crystalline hybrid photochromic materials (CHPMs) can not only preserve the intrinsic features of photochromic materials but also coin new photoresponsive functionality derived from the synergy of each components. The crystalline characteristics feature unique advantages in understanding structure–property relationships and mechanisms, which provides the possibility to explore potential photoresponsive mechanisms. This review summarizes the recent advances in CHPMs driven by electron transfer (ET) with focus on molecular design, assembly strategy and structure-related photoresponsive properties. The first unit offers a short discussion of CHPMs and the general ET strategies for the design of CHPMs. The following sections give overviews of CHPMs based on pyridinium-derivatives, CHPMs based on naphthalene diimide-derivatives, CHPMs based on conjugated N-heterocycle units, CHPMs based on metallocyanate. Finally, we will give the conclusions and perspectives of CHPMs. The trends identified in this review could propel the design and application of CHPMs and photoresponsive materials.

Two layered zincophosphites constructed from an emissive linker molecule were prepared. The ligand connects zincophosphite chains or clusters to form two distinct two-dimensional hybrid frameworks in two compounds. The coordinating effect of an organic ligand to Zn centers increases the rigidity and results in room temperature phosphorescence.

With lanthanide (Ln) cations acting as templates, a series of iodoargentates were successfully constructed, {[Ln(H2O)8][Ag8I11]}n [Ln = Eu3+ (1-Eu), Tb3+ (1-Tb)], {[Ln(DMF)8][Ag6I9]}n [Ln = Eu3+ (2-Eu), Tm3+ (2-Tm), DMF = N,N-dimethylformamide], and {[Ln(H2O)8[Ag15I18]}n [Ln = Eu3+ (3-Eu), Tb3+ (3-Tb)]. The iodoargentates feature special luminescent performance through the introduction of Ln3+ ions, which is demonstrated by corresponding Eu-, Tb-, Tm-based compounds exhibiting characteristic emission bands as well as distinctive emission colors. Moreover, the iodoargentate with doped Ln cations {[Eu0.531Tb0.117Tm0.352(DMF)8][Ag6I9]}n (2-Eu0.531Tb0.117Tm0.352) was finally obtained, displaying a white light emission under UV excitation at room temperature.