Search

The discovery of pyramidal inversion has continued to impact modern organic and organometallic chemistry. Sequential alkylation reactions of an N-heterocyclic carbene (NHC) ligated dicarbondiphosphide 1 with RI (R = Me, Et, or iBu) and ZnMe2 give rise to the highly stereoselective synthesis of cis-1,3-diphosphetanes 3. cis-3 is conformationally favorable at room temperature, whereas inversion to trans-3 is observed at 110 °C. One-electron oxidation of cis-3 with Fc+(BArF) (Fc = [Fe(C5H5)2]; BArF = [B(3,5-(CF3)2C6H3)4)]-) leads to the stereoselective formation of trans-1,3-diphosphetane radical cation salts 3•+(BArF), which can be reversibly transformed to cis-3 upon one-electron reduction. Salts 3•+(BArF) represent the first examples of 1,3-diphosphetane radical cations. These results provide a potential application of planar four-membered heterocycle-based building blocks for electrically fueled molecular switches.

Metal complexes of 1,2-diamidobenzenes have been long studied because of their intriguing redox properties and electronic structures. We present here a series of such complexes with 1,2-bis(sulfonamido)benzene ligands to probe the utility of these ligands for generating a large zero-field splitting (ZFS, D) in metal complexes that possibly act as single-ion magnets. To this end, we have synthesized a series of homoleptic ate complexes of the form (X)n[M{bis(sulfonamido)benzene}2] (n equals 4 minus the oxidation state of the metal), where M (Fe/Co/Ni), X [K+/(K-18-c-6)+/(HNEt3)+, with 18-c-6 = 18-crown ether 6], and the substituents (methyl and tolyl) on the ligand [bmsab = 1,2-bis(methanesulfonamido)benzene; btsab = 1,2-bis(toluenesulfonamido)benzene] were varied to analyze their effect on the ZFS, possible single-ion-magnet properties, and redox behavior of these metal complexes. A combination of X-ray crystallography, (spectro)electrochemistry, superconducting quantum interference device magnetometry, high-frequency electron paramagnetic resonance spectroscopy, and Mossbauer spectroscopy was used to investigate the electronic/geometric structures of these complexes and the aforementioned properties. These investigations show that the cobalt(II) complexes display very high negative D values in the range of -100 to -130 cm-1, and the nickel(II) complexes display very high positive D values of 76 and 58 cm-1. In addition, the cobalt(II) complexes shows barriers of 200-260 cm-1 and slow relaxation of the magnetization in the absence of an external magnetic field, underscoring the robustness of this class of complexes. The iron(II) complex exhibits a D value of -3.29 cm-1 and can be chemically oxidized to an iron(III) complex that has D = -1.96 cm-1. These findings clearly show that bis(sulfonamido)benzenes are ideally suited to stabilize ate complexes, to generate very high ZFSs at the metal centers with single-ion-magnet properties, and to induce exclusive oxidation at the metal center (for iron) despite the presence of ligands that are potentially noninnocent. Our results therefore substantially enhance the scope for this class of redox-active ligands.

The rational design and synthesis of highly efficient electrocatalysts for oxygen evolution reaction (OER) is of critical importance to the large-scale production of hydrogen by water electrolysis. Here, we develop a bimetallic, synergistic, and highly efficient Co-Fe-P electrocatalyst for OER, by selecting a two-dimensional metal-organic framework (MOF) of Co-ZIF-L as the precursor. The Co-Fe-P electrocatalyst features pronounced synergistic effects induced by notable electron transfer from Co to Fe, and a large electrochemical active surface area achieved by organizing the synergistic Co-Fe-P into hierarchical nanosheet arrays with disordered grain boundaries. Such features facilitate the generation of abundant and efficiently exposed Co

International audience; The development of cost-effective, high-performance, and robust bifunctional electrocatalysts for overall water splitting remains highly desirable yet quite challenging. Here, by selecting appreciate precursors of dopamine and a Co-containing metal-organic framework of ZIF-67, we subtly couple their reaction processes to develop a facile approach for the synthesis of a hollow CoP nanostructure with N-doped carbon skeleton (H-CoP@NC). Benefiting from the highly porous nanostructure and conductive carbon skeleton, H-CoP@NC is capable of working as highly active and durable bifunctional electrocatalyst for both hydrogen and oxygen evolution reaction. When further used as the electrocatalyst for overall water splitting, H-CoP@NC delivers excellent activity (cell voltage of 1.72 V at a current density of 10 mA cm(-2)), close to that of the noble-metal-based benchmark catalyst couple of Pt/C parallel to RuO2. Our work thus provides new insights into the development of transitional metal phosphides based hollow hybrid nanostructures, particularly those with multiple functionalities in sustainable energy conversion technologies and systems.

A new Cu4I4-cluster-based compound is constructed to show multifaceted photoluminescent attributes: (1) ultraviolet (UV)-excited thermo-, mechano-, and rigido-chromic phosphorescence by the OPA (one-photon absorption) pathway, due to the interchanging emissions from cluster-centered (3CC) and halide-to-ligand charge-transfer (3XLCT) excited triplet states, (2) the ability to convert X/γ-ray and near-infrared (NIR) radiation to visible-light emission, in which the heavy Cu4I4 cores serve as the efficient X/γ-PEA (photoelectric absorption) or NIR-TPA (two-photon absorption) trapper and convertor to photons in the visible spectrum from the same emissive triplet states as those produced by UV excitation. This all-in-one compound affords a highly integrated nanolab for understanding and exploiting a wide range of photophysical phenomena simultaneously and is further fabricated into fiber-coupled long-range, in situ cryogenic thermometer and poly(methyl methacrylate) (PMMA)-embedded monolith gel, providing access to advanced applications in multifunctional optical materials and devices.

During the past few decades, great efforts have been devoted to the design and self-assembly of discrete metal–organic cages/containers (MOCs) with increasing complexity and functionality. Among which, the incorporation of chirality into the construction of MOCs endows these supramolecular containers with unique potentials in stereochemical, nonlinear optical, biomedical and enzyme mimical fields. In this review, we give a brief survey of recent works focusing on the assembly and applications of chiral metal–organic convex polyhedra with well-defined three-dimensional (3D) outer shapes and inner cavities, including a few examples of chiral MOCs in other configurations. In general, the stereochemical origin of a chiral MOC can be generated through geometrical symmetry control pathways by removing the inherent inversion and/or mirror symmetries, in which the vertice-, edge-, and face-directed assembling approaches represent the most successful strategies to introduce stereogenic centers into and achieve absolute chiral environments in MOCs. Stereochemical memory, transfer and communication can be realized among different components of chiral MOCs in a supramolecular sense, resulting in cooperative and synergetic effects of chiral complex systems, which can be further explored for enantio-recognition, separation and asymmetric catalysis applications.

Luminescent thermometers have attracted much attention, because of their fast response, high sensitivity, and noninvasive operation, relative to other traditional thermometers. The extensive studies on the temperature-dependent luminescent properties of Cu(I) complexes make this low-cost metal source a promising candidate as a component of thermometers. Herein, we prepared three luminescent phosphinine Cu(I) complexes whose emission lifetimes are precisely dependent on the temperature variations. For practical utilization, sensor films have been fabricated by doping these Cu(I) complexes into the matrices of polyacrylamide. These films not only exhibit excellent linear correlations between the temperature and emission lifetime over the wide range of 77-337 K, but also show high sensitivity (with the best one to -6.99 μs K-1). These are essential factors for the application in luminescent molecular thermometers. Moreover, the emission mechanism for these Cu(I) complexes are rationalized by the combination of experimental and theoretical results.

A rhodium(III)-porphyrin zirconium metal-organic framework (Rh-PMOF-1(Zr)) has been prepared from the self-assembly of a Rh-based metalloporphyrin tetracarboxylic ligand Rh(TCPP)Cl (TCPP = tetrakis(4-carboxyphenyl)porphyrin) with ZrCl4. The framework of Rh-PMOF-1 is stable up to 270 °C as disclosed by the variable-temperature powder X-ray diffraction (VT-PXRD) measurements, and possesses good chemical stability over a wide range of solvents including water. The single-crystal structural analysis reveals that Rh-PMOF-1 contains 3-D channels (1.9 × 1.9 nm2), and the Rh-porphyrin units are exposed to the cavities. The calculation based on the N2 adsorption at 77 K shows Rh-PMOF-1(Zr) has a high BET surface area (3015 m2g−1). The luminescence decay of Rh-PMOF-1 is well fitted to a tri-exponential curve featuring a long average lifetime of 207 μs at 298 K under vacuum, which represents a rare example of room-temperature phosphorescence of Rh-porphyrin complexes. Under 1 atm, it displays CO2 uptake up to 42, 53 and 98 cm3g−1 at 308, 298 and 273 K, respectively. Catalytic results show that, under the visible light (≥400 nm) irradiation without any additional photosensitizer, Rh-PMOF-1 is powerful to catalyze CO2 reduction to the formate ion with up to 99% selectivity, and can be recycled and reused for 3 runs. Theoretical study was further carried out to reveal the energy levels of the frontier orbitals of Rh-PMOF-1 and the preferred binding sites of CO2 in the framework.

A Co-MOF, [Co3(HL)2·4DMF·4H2O] was simply synthesized through a one-pot solvothermal method. With the semiconductor nature, its band gap was determined to be 2.95 eV by the Kubelka–Munk method. It is the first trinuclear Co-MOF employed for photocatalytic hydrogen evolution and CO2 reduction with cobalt–oxygen clusters as catalytic nodes. Hydrogen evolution experiments indicated the activity was related to the photosensitizer, TEOA, solvents, and size of catalyst. After optimization, the best activity of H2 production was 1102 μmol/(g h) when catalyst was ground and then soaked in photosensitizer solution before photoreaction. To display the integrated design of Co-MOF, we used no additional photosensitizer and cocatalyst in the CO2 reduction system. When −NH2 was used for light absorption and a Co–O cluster was used as catalyst, Co-MOF exhibited an activity of 456.0 μmol/(g h). The photocatalytic mechanisms for hydrogen evolution and CO2 reduction were also proposed.

Searching for highly active and stable bifunctional electrocatalysts for overall water splitting, e.g., for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), is dominating in terms of bringing future renewable energy storage and conversion processes to reality. In this work, a kind of two-dimensional ultrathin manganese (Mn) doped polyhedral cobalt phosphide (Mn-CoP) has been synthesized via the etching-carbonization-phosphidation of Co-centered metal-organic frameworks. The as-prepared porous Mn-CoP nanosheets had a larger specific surface area and higher porosity, furnishing them with more plentiful catalytically active sites than their counterpart hollow CoP and Mn-CoP nanoparticles, and thus showed much better electrocatalytic activity for both HER and OER in acidic and alkaline media. In addition, the Mn-CoP nanosheets also demonstrated excellent durability after long-term operation. These high performances are attributed to the synergistic effects of the CoP nanosheets with intrinsic activity, the graphitic carbon and the controllable electronic structure doped by Mn and N elements. This synthetic methodology of using a classical MOF as a precursor to build a new 2D sheet-like composite may create opportunities to search for highly efficient and robust non-precious metal catalysts for energy-related reactions.

A stable and porous porphyrinic metal–organic framework, Ru-PMOF-1(Hf), has been prepared through the self-assembly of [5,10,15,20-tetrakis(4-carboxyphenyl)porphyrinato](monocarbonyl)ruthenium (Ru(TCPP)(CO)) and HfCl4. Single-crystal X-ray diffraction analysis reveals that Ru-PMOF-1(Hf) possesses a three-dimensional (3D) structure with orthogonal 1D open channels of 1.9 × 1.9 nm2. The porous nature has been confirmed by gas adsorption measurements. Its catalytic activity for the carbene insertion into N–H bonds has been investigated. The catalytic results indicate that Ru-PMOF-1(Hf) is efficient for the insertion reactions of ethyl 2-diazoacetate (EDA) into a range of secondary amines with up to 92% yield, 938 TON and 2475 h−1 TOF. As an excellent heterogeneous catalyst, Ru-PMOF-1(Hf) can be recovered and reused for at least ten runs with negligible loss of catalytic activity. Due to its uniform microporosity in three orthogonal directions, Ru-PMOF-1(Hf), of which the particle sizes were carefully controlled by sieving, can induce size selectivity regarding the amine substrates. The reactivities of different unbranched dialkylamines, such as diethylamine (NHEt2), dibutylamine (NHBu2) and dipentylamine (NHPent2), have been compared, and the results display an apparent decreasing trend along the chain lengthening. For comparison, the corresponding nonporous and homogeneous catalyst Ru(TMCPP)(CO) (TMCPP = tetrakis(4-methoxycarbonylphenyl)porphyrin) displays negligible difference towards the reactions with these three amines.

Lithium-ion batteries (LIBs), the impeccable energy storage systems for commercial applications, have been facing the threat of shortage due to the receding levels of lithium resources (20 ppm) in earth’s crust. Research focused on identifying alternate energy storage systems leads to the invigorating growth of potassium ion batteries (PIBs) as prominent candidates owing to the similar electrochemical properties of lithium and abundant resources of potassium. The electrochemical performance and cost of a battery device are believed to have mainly centered around its electrode material. In this review, we are motivated to mainly focus on the progress of emerging MOF chemistry as PIB electrodes in order to achieve good electrochemical performance in PIBs. The rational synthesis methods enable the modulation of key factors such as nanoscale size, rational construction, tailorable porosity, hybrid composition, and structural engineering in MOFs and/or MOF-derived materials were discussed in this review, which can enhance redox properties, alleviate internal stress, provide large interstitial sites, open channels for ion transportation, improve active surface area of electrode material, and further enhance electrode/electrolyte interaction, facilitating distinguished potassium storage capacity in PIBs with superior rate capability and long-term cycling life etc. aspects. The unique characteristics of MOFs and MOF derivatives (carbons, alloying-type metals, metal selenides, metal sulfides, and metal phosphides) including structure, composition, dimensions, and porosity are conducive to their boosted electrochemical performance as anodes and cathodes in PIBs. This review is expected to provide new perspectives and deeper insights into MOF chemistry and its application as advanced PIBs electrodes towards the high electrochemical performance.

A three-dimensional functional metal–organic framework (LIFM-38) has been successfully synthesized with a fluorinated bicarboxylate ligand. LIFM-38 exhibits good stability and a surface area of 803 m2 g–1. Owing to the synergistic effect of different functional groups, cocrystallized amine active sites, and suitable pore space, LIFM-38 shows good selective CO2 and C2+ hydrocarbons adsorption over CH4 and N2; in addition, LIFM-38 exhibits good selective C3 hydrocarbons adsorption over C2 hydrocarbons.

A novel Al(III)-4-tert-butylpyridine (TBP) gel electrolyte is successfully achieved by a simple and facile in situ gelation method and applied as quasi-solid-state electrolyte for dye-sensitized solar cells (DSSCs). Through directly adding Al3+ into the TBP solution, the induced hydrolysis of Al3+ and the coordination interaction between Al3+ and TBP facilitates the formation of metal-organic gels(MOGs), in which such bi-functional TBP molecules will act as both gelators and active additives to tailor the performance of electrolytes. In addition, the gel electrolytes can largely preserve the properties of liquid electrolyte and penetrate well into the TiO2 photoanode film. Both Al3+ and TBP in the gel electrolytes affect the performance of cells. The Jsc of gel electrolytes decrease with the increasing concentration of gelators due to the enhanced strength and viscosity of the gel electrolytes, while the competition between Al3+ and TBP causes conduction band edge shift and electron recombination, leading to a variation of Voc. Herein, by tuning the molar ratio of Al3+/TBP, an impressive conversion efficiency of 8.25% is obtained, indicating a promising protocol of preparing MOGs not only to achieve high performance in solar cells, but also opens up extended scopes in other energy-related fields such as catalysis.

Near-infrared (NIR) luminescence detection of picric acid (PA) was achieved sensitively and selectively by using a nanosized Nd-III metal-organic cage (MOC) for the first time.

Cesium lead iodide perovskite (CsPbI3) has been proposed as an efficient alternative to modify the instability of methylammonium lead iodide (MAPbI3) under thermal and humidity stress. However, three-dimensional (3D) cesium lead iodide forms an undesirable non-perovskite structure with a wide bandgap at ambient atmosphere. Herein, dimension engineering is employed by introducing a bulky ammonium cation to form stable 2D cesium lead iodide perovskite BA2CsPb2I7 (BA = CH3(CH2)3NH3), which not only exhibits prominent optoelectronic properties, but also possesses superior structural and compositional stability to 3D CsPbI3 and MAPbI3 under the pressure of heat and humidity. The current 2D BA2CsPb2I7 shows excellent stability after exposure to 30% relative humidity for 30 days or upon heating at 85 °C for 3 days. In addition, the corresponding BA2CsPb2I7 based planar perovskite solar cells retain 92% of the initial power conversion efficiency (PCE) after aging for over 30 days without any encapsulation, demonstrating the up-scalability of 2D perovskite compounds as stable and efficient light-absorbing materials for perovskite solar cells and other optoelectronic applications.

Hydrophobic metallo-supramolecular cages are selectively encapsulating hydrophilic zwitterionic guests in organic solvents via synergetic multivalent recognition.

A trifluoromethyl functionalized linker and Cu-O chain composed MOF, LIFM-100, was used as "crystalline sponge" to determine eight hardly crystallized liquids' configurations based on its flexibility conformation, suitable pore size, electron-rich channel environment, and low symmetric space group. The H bond interactions between host-guest and guest-guest were well analyzed.

A new series of cyclometalated platinum(II) complexes of N^C^N ligands, where N^C^N = 1,3-bis(1-n-alkylpyrazol-3-yl)benzene (bpzb), namely, [Pt(bpzb)Cl] (1 and 2) and [Pt(bpzb)(C≡C-R)] (3-10) (R = C6H5, C6H4-OCH3-p, C6H4-NO2-p, C6H4-NH2-p, 4-cholesteryl phenyl carbamate, and cholesteryl methylcarbamate) were synthesized and characterized. Their electrochemical and photophysical properties were investigated. Two of the platinum(II) complexes were also structurally characterized by X-ray crystallography, and short intermolecular C-H···Pt contacts were observed. Vibronic-structured emission bands originating from triplet IL (3IL) excited states of the bpzb ligands with mixing of some 3MLCT [dπ(Pt)→π*(bpzb)] character were observed in solution state. Interestingly, complex 5 shows a low-energy emission that is derived from the involvement of the p-nitrophenylethynyl ligand. Complex 9 with hydrophobic cholesteryl 4-ethynylphenyl carbamate ligand was found to form stable metallogels in several organic solvents, which are responsive to mechanical sonication and thermal stimuli and show circular dichroism activity.

Cupric oxide (CuO), a narrow-bandgap semiconductor, has a band alignment that makes it an ideal photocathode for the renewable production of solar fuels. However, the photoelectrochemical performance of CuO is limited by its poor conductivity and short electron diffusion lengths. Herein, a three-dimensional (3D) architecture consisting of CuO nanosheets supported onto transparent conducting macroporous antimony-doped tin oxide (mpATO@CuONSs) is designed as an excellent photocathode for promoting the hydrogen evolution reaction (HER). Owing to the 3D structure affording superior light-harvesting characteristics, large contact areas with the electrolyte, and highly conductive pathways for separation and transport of charge carriers, the mpATO@CuONSs photocathode produces an impressively high photocurrent density of −4.6 mA cm−2 at 0 V versus the reversible hydrogen electrode (RHE), which is much higher than that of the CuONSs array onto planar FTO glass (−1.9 mA cm−2).

Two hydrophobic hole transporting materials (HTMs) carrying multiple thiophene cores of 5,7-bis(3-hexylthiophen-2-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxine (for SP-01 ) or 4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene (for SP-02 ) and long alkyl substituents have been prepared through facile routes with high yields, together with the hole-transporting molecule 2,5-bis(4,4′-bis(methoxyphenyl)aminophen-4′′-yl)-3,4-ethylene dioxythiophene ( H101 ) as reference compound. The structure-property relationships of these HTMs for perovskite solar cells have been systematically investigated. It is found that introducing hydrophobic alkyl chains into HTMs can retard interfacial charge recombination and, specifically, improve stability owing to the enhanced moisture resistance. Perovskite solar cells based on SP-01 give an overall conversion efficiency of 12.37% without, and 13.91% with the addition of FK102 , respectively. These values are better than that of H101 (11.59%) and comparable to that of the standard spiro-OMeTAD (12.95%). Moreover, the devices based on hydrophobic HTMs SP-01 show better stability under ∼40% humid atmosphere than those based on H101 and spiro-OMeTAD, which paves the way for developing new HTMs combining high efficiency, low cost, and excellent stability features by appropriate structural modifications.

Metal-organic frameworks (MOFs) including the UiO-66 series show potential application in the adsorption and conversion of CO2 . Herein, we report the first tetravalent metal-based metal-organic gels constructed from Zr(IV) and 2-aminoterephthalic acid (H2 BDC-NH2 ). The ZrBDC-NH2 gel materials are based on UiO-66-NH2 nanoparticles and were easily prepared under mild conditions (80 °C for 4.5 h). The ZrBDC-NH2 -1:1-0.2 gel material has a high surface area (up to 1040 m(2) g(-1) ) and showed outstanding performance in CO2 adsorption (by using the dried material) and conversion (by using the wet gel) arising from the combined advantages of the gel and the UiO-66-NH2 MOF. The ZrBDC-NH2 -1:1-0.2 dried material showed 38 % higher capture capacity for CO2 at 298 K than microcrystalline UiO-66-NH2 . It showed high ideal adsorbed solution theory selectivity (71.6 at 298 K) for a CO2 /N2 gas mixture (molar ratio 15:85). Furthermore, the ZrBDC-NH2 -1:1-0.2 gel showed activity as a heterogeneous catalyst in the chemical fixation of CO2 and an excellent catalytic performance was achieved for the cycloaddition of atmospheric pressure of CO2 to epoxides at 373 K. In addition, the gel catalyst could be reused over multiple cycles with no considerable loss of catalytic activity.

Multi-mode photoluminescence, including enolemission, keto-emission, and aggregate-related emission is achieved in a Zn-II coordination polymer from excited-state intramolecular proton transfer (ESIPT) ligands. Single-phase white light emission (WLE) and tunable emitting colors can be obtained by varying the suspending/grinding solvent system or temperature, which brings a brand-new model in developing multi-stimuli-responsive WLE materials.

A series of (metallo)porphyrin imine gels have been synthesized based on imine chemistry. The resulting aerogels have sponge-like porous networked structures consisting of interconnected nanoparticles with hierarchical porosity. The aerogels have high specific surface areas (up to 719 m2 g−1) and large pore volumes (up to 2.60 cm3 g−1). The effect of metal ions on the uptake of gases in these aerogels was investigated. The impregnation of various metal ions (Pd(II), Ni(II), Mn(III), Fe(III) and Sn(IV)) enhances the uptake capacity of various gases (e.g., CO2) despite their higher densities. Among the metal ions, Pd(II) is the best to increase the adsorption capacity and the isosteric heat of CO2 adsorption. The Pd-tapp–A4 aerogel exhibits CO2 volumetric uptake (1.62 mmol g−1, 7.13 wt% at 298 K, 1 bar) with a high isosteric heat of adsorption (40.0 kJ mol−1). The gels also show potential applications in catalysis because of their unique hierarchical porosity and the availability of metal centers. In combination with microfluidic technology, a catalytic gel capillary reactor has been assembled with the Pd-tapp–A4 gel supported on the inner surface of a functionalized capillary.

A novel phosphine-based tetragonal cage has been assembled from a tetraphenylethylene (TPE)-based tetraphosphine and Ag(+) ions. The cage structure is maintained both in solutions and in the solid state. emits strong fluorescence not only in dilute solutions but also in aggregated states. The turn-on fluorescence of TPE-P4 in dilute solutions is attributed to the formation of . shows potential as a fluorescent sensor towards anions and olefin compounds, which arises from binding of the guest anions/olefin compounds by its labile silver centres.

A tetrapodal zwitterionic-type ligand featuring both AIE (aggregation-induced emission) and ILCT (intraligand charge transfer) properties, namely 1,1',1'',1'''-(4,4',4'',4'''-(ethene-1,1,2,2-tetrayl)tetrakis(benzene-4,1-diyl))tetrakis(methylene)tetrapyridin-4(1H)-one (TPE-4PO) has been designed and applied to the assembly of lanthanide complexes LIFM-21(Ln) (Ln = Sm, Eu, Gd, Tb and Dy). Apart from sensitization of NIR emission of Sm(3+) and Dy(3+), the resulting ligand and lanthanide complexes show both AIE and ILCT-related photoluminescence behaviors. The photo-response of this system to different aggregation states, solvents' polarity and mechanical grinding was demonstrated by distinguishable emission intensities and colours.

Self-assembly of a new metalloporphyrin tetracarboxylic ligand Ir(TCPP)Cl (TCPP = tetrakis(4-carboxyphenyl)porphyrin) with ZrCl4 in the presence of benzoic acid leads to the formation of a three-dimensional (3D) iridium(III)-porphyrin metal–organic framework (Ir-PMOF) with the formula of [(Zr6(μ3-O)8(OH)2(H2O)10)2(Ir(TCPP)Cl)3]·solvents (Ir-PMOF-1(Zr)), which possesses square-shaped channels of 1.9 × 1.9 nm2 (atom-to-atom distances across opposite Ir metal atoms) in three orthogonal directions as disclosed by the single-crystal X-ray diffraction analysis. Ir-PMOF-1(Zr) represents the first MOF bearing a self-supporting iridium-porphyrin catalytic framework, featuring high porosity and stability. The catalytic tests disclose that the activated Ir-PMOF-1(Zr) can promote O–H insertion with a turnover frequency (TOF) up to 4260 h−1. Ir-PMOF-1(Zr) can be recycled and reused for 10 runs without significant loss of catalytic activity, and the total turnover number (TON) for O–H insertion after 10 successive runs reaches 875.

Metal–organic frameworks (MOFs) are the newly crystalline porous materials with outstanding structural, compositional, and morphological features, which have garnered much attention in all dimensions of major scientific and engineering fields, including energy storage and conversion. Various pristine MOFs and their derivatives have been developed and used as anode materials in lithium–ion batteries (LIBs). In this review, we specifically focused on MOFs–derived nanostructured metal oxides with diverse structural and compositional features that exhibit exceptional lithium storage capacity. These intriguing nanostructures inherit the multidimensional structure of MOF and the advantage of even distribution of metallic species after thermal decomposition, which facilitates fast reaction kinetics of lithium transportation and ultimately improves the battery performance. Herein, we review and categorise the synthetic strategies to achieve various transitional metal oxide nanostructures/composites obtained from BDC/BTC–based MOFs (H2BDC = 1,4–benzenedicarboxylic acid, H3BTC = 1,3,5–benzenetricarboxylic acid), zeolitic imidazolate frameworks (ZIFs), Prussian blue and Prussian blue analogues (PB and PBAs), and other unusual porous crystalline MOF materials. In addition, we will also compare the electrochemical performances of various metal oxides (MOs) nanostructures obtained via heteroatom doping in the pristine MOF precursor or by tuning their structure. Finally, our discussion will focus on the advantages and future developments in design and fabrication of new MOF–derived metal oxide electrode materials with high energy efficiencies in relation with the next generation rechargeable battery applications.

In the series of homo-leptic trinuclear complexes {[Ln3(L)4Cl4(MeOH)(H2O)]·Cl} (Ln = La, 1; Ln = Eu, 2; Ln = Tb, 3 or Ln = Gd, 4) self-assembled from the allyl-modified benzimidazole-type ligand HL (4-allyl-2-(1H-benzo[d]imidazol-2-yl)-6-methoxyphenol) and LnCl3·6H2O, a suitable energy level match endows efficient green luminescence (Φoverall = 72%) of Tb3-arrayed complex 3. The copolymerization between each of these complex monomers 1–4 and CC-containing MMA (methyl methacrylate) or NBE (norbornene) shows that degradative chain transfer of the terminal four flexible allyl groups within restrains their radical polymerization with MMA while it does not hinder their effective ring-opening metathesis polymerization (ROMP) with NBE. Thus, two kinds of PMMA-supported doping hybrid materials 1@PMMA, 2@PMMA, 3@PMMA and 4@PMMA and PNBE-supported metallopolymer-type hybrid materials Poly(NBE-1), Poly(NBE-2), Poly(NBE-3) and Poly(NBE-4) are obtained, respectively. Especially for both 3@PMMA and Poly(NBE-3) with high color-purity characteristic green emission of Tb3+ ions, improved physical properties including significantly enhanced luminescence (Φoverall = 76% or 83%) are observed, and covalent-bonding endows a higher-concentration self-quenching as compared to physical doping.

In order to explore the supramolecular solid-state structural and packing transformations and the property tuning as a function of reaction time, a tripodal triBZ-ntb (4,4′,4′′-(2,2′,2′′-nitrilotris(methylene)tris(1H-benzo[d]imidazole-2,1-diyl)tris(methylene))tribenzonitrile) ligand was self-assembled with cadmium chloride by applying a hydrothermal method for differing reaction times. Three coordination structures were obtained, namely, [Cd(triBZ-ntb)Cl]2(CdCl4)·2H2O·2DMF (Cd5), [Cd(triBZ-ntb)Cl2]·3H2O (Cd10), and [Cd(triBZ-ntb)Cl]2(CdCl4)·2H2O (Cd20), and characterized by IR, EA, single crystal and powder X-ray diffraction methods. Cd5 and Cd20 have identical coordination monomers, [Cd(triBZ-ntb)Cl]+ and (CdCl4)2− counter anions, with a total metal-to-ligand ratio of 3 : 2, but with slightly different packing states. Meanwhile, the intermediate compound Cd10 is composed of only a neutral coordination unit [Cd(triBZ-ntb)Cl2], with a metal-to-ligand ratio of 1 : 1, by the additional coordination of one Cl− to the Cd(II) metal center. During the structural transformation process, the formation of (CdCl4)2− counter anions in Cd5 and Cd20 serves as an auxiliary “cabinet” for the storage of surplus Cd2+ metal ions. Theoretical study reveals the relative energy changes in the transformation processes. Furthermore, the switchable structures and packing states in these complexes result in tunable luminescent properties.

Multichromophoric dye-sensitized solar cells (DSSCs) based on the dual sensitization with a metal–organic combinatorial dye comprised of a ruthenium complex and an organic triphenyl amine dyad have been constructed, which convert light into electrical energy with a higher power conversion efficiency and incident-photon-to-current efficiency than the devices made of individual inorganic and organic dyes.

Sodium phosphaethynolate, Na(OCP), reacts with the bulky P-chloro-diazaphosphole yielding a phosphanyl phosphaketene, which is stable for weeks under an inert atmosphere in the solid state. This compound is best described as a tight ion pair with a remarkably long P-P bond distance (2.44 Å). In solution, this phosphaketene dimerizes under loss of CO to give 1,2,3-triphosphabicyclobutane identified by an X-ray diffraction study. As an intermediate, a five-membered heterocyclic diphosphene was trapped in a Diels-Alder reaction with 2,3-dimethylbutadiene. The formation of this intermediate in a hetero-Cope-rearrangement as well as dimerization/CO loss were computed with various DFT methods which allowed us to understand the reaction mechanisms.

Two porous coordination polymers, Co-Py2PO and Co-Py2PO′, have been obtained via reactions of in situ oxidized terpyridyl phosphines and cobalt(II) nitrate. Single-crystal structure analysis reveals that Co-Py2PO′ has a three-dimensional (3D) structure with (8·102)(83) net topology, while the structural analysis of Co-Py2PO reveals a 2D polycatenated framework consisting of two sets of parallel 2D networks of (63) net topology. For Co-Py2PO′, guest CHCl3 molecules are locked in the channels along the b axis by P(O)Ph2 phenyl rings and coordinated nitrate ions, and cannot be released out of the host framework. In contrast, the as-synthesized 2D framework Co-Py2PO readily loses its solvated guest molecules to give an activated amorphous material for sorption. Activated Co-Py2PO has a flexible structure and shows dynamic adsorption behaviours towards various guests (N2 and benzene). The flexibility may arise from the combination of layer–layer motion and the local flexibility of the P–C bond of –P(O)Ph2 groups.

Porous Co–P–Pd nanotube arrays (NTAs) are prepared and used for catalyzing the hydrolysis of alkaline NaBH4 solution to generate H2. Benefiting from the unique porous structure and synergistic effect, the Co–P–Pd NTAs show a maximum hydrogen generation rate of 4216 mL per min per g catalyst and good cyclic stability.

A series of homochiral metal-organic cages (MOCs) have been obtained from self-assembly of Cu(II) salts with chiral N,N'-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-amino acids. Single-crystal X-ray diffraction analyses reveal that these compounds show a lantern-type cage structure, in which one pair of Cu2(CO2)4 paddlewheels is linked by four diacid ligands. The resulting homochiral cages have been fully characterized by EA, TOF-MS, TGA, VTPXRD, IR, UV, and CD measurements. The catalytic tests reveal that these Cu(II) cages are effective in cyclopropanation with excellent diastereoselectivity (up to 99 : 1 E/Z). In addition, the cage catalysts can promote the aziridination reaction with PhI=NNs.

The complete structure of non-crystalline compounds can be determined by confining them in crystalline structures. The reduced motional degrees of freedom of encapsulated guests can be obtained through their anchoring to the host cages, which results in the reduction of a significant amount of disorder. The "pyrene box" cages that easily crystallize from aqueous solutions are recommended to achieve complete structure elucidation of compounds of biological interest. In this study, the "pyrene box" cages have been used for the in situ encapsulation of biogenic amines: histamine, dopamine, and serotonin. NMR spectroscopy illustrates that these systems are stable in aqueous solution. The X-ray single-crystal structure analysis reveals that the pyrene box/biogenic amine systems are stabilized through combined interactions, strongly contributing to in situ fixation and accurate determination of their crystal structures.

A series of isolated binuclear copper(I) thiolate and selenolate complexes [Cu2(ER)2(dpppt)2] (1, E = S, R = C4H3S; 2, E = S, R = p-C6H4OMe; 3, E = Se, R = C6H5; 4, E = Se, R = p-C6H4SMe; 5, E = Se, R = p-C6H4NMe2) was synthesized. It was found that the luminescence of these complexes could be modulated by the chalcogenolate ligands. The five complexes show optical transitions with HOMO–LUMO gaps of ca. 2.95 eV (1), 2.82 eV (2), 2.99 eV (3), 2.95 eV (4) and 2.64 eV (5), respectively. Two of them (2 and 5) show a significant luminescence at room temperature at 465 or 480 nm, respectively. This might most probably result from the influence of the electron donating nature of the substituents –OMe and –NMe2.

On the basis of self-assembly from the divinylphenyl-modified Salen-type Schiff-base ligands H2L(1) (N,N'-bis(5-(3'-vinylphenyl)-3-methoxy-salicylidene)ethylene-1,2-diamine) or H2L(2) (N,N'-bis(5-(3'-vinylphenyl)-3-methoxy-salicylidene)phenylene-1,2-diamine) with Zn(OAc)2·2H2O and Ln(NO3)3·6H2O in the presence of pyridine (Py), two series of heterobinuclear Zn-Ln complexes [Zn(L(n))(Py)Ln(NO3)3] (n = 1, Ln = La, 1; Ln = Nd, 2; or Ln = Gd, 3 and n = 2, Ln = La, 4; Ln = Nd, 5; or Ln = Gd, 6) are obtained, respectively. Further, through the physical doping and the controlled copolymerization with methyl methacrylate (MMA), two kinds of PMMA-supported hybrid materials, doped PMMA/[Zn(L(n))(Py)Ln(NO3)3] and Wolf Type II Zn(2+)-Ln(3+)-containing metallopolymers Poly(MMA-co-[Zn(L(n))(Py)Ln(NO3)3]), are obtained, respectively. The result of their solid photophysical properties shows the strong and characteristic near-infrared (NIR) luminescent Nd(3+)-centered emissions for both PMMA/[Zn(L(n))(Py)Nd(NO3)3] and Poly(MMA-co-[Zn(L(n))(Py)Nd(NO3)3]), where ethylene-linked hybrid materials endow relatively higher intrinsic quantum yields due to the sensitization from both (1)LC and (3)LC of the chromorphore than those from only (1)LC in phenylene-linked hybrid materials, and the concentration self-quenching of Nd(3+)-based NIR luminescence could be effectively prevented for the copolymerized hybrid materials in comparison with the doped hybrid materials.

The first examples of Wolf Type II Zn2Ln-containing metallopolymers poly{MMA-co-[Zn2(L)2(4-vp)2Ln(NO3)3]} (Ln = La, Nd, Yb, Er, Gd; H2L = N,N′-bis(salicylidene)ethylene-1,2-diamine; 4-vp = 4-vinylpyridine; MMA = methyl methacrylate) are obtained from the controlled copolymerization of heterotrinuclear Zn2Ln-arrayed complexes [Zn2(L)2(4-vp)2Ln(NO3)3] (Ln = La, 1; Ln = Nd, 2; Ln = Yb, 3; Ln = Er, 4; Ln = Gd, 5) with MMA. The strong and characteristic near-infrared (NIR) luminescent Ln3+-centered emission for each of the PMMA-supported poly{MMA-co-[Zn2(L)2(4-vp)2Ln(NO3)3]} (Ln = Nd, Yb, Er) hybrid materials is retained with somewhat higher intrinsic quantum yields than those of the respective Zn2Ln-arrayed complex. Especially for poly(MMA-co-3), which has more efficient sensitization from both ligand-centered singlet (1LC) and triplet (3LC) states of the chromophores, the concentration self-quenching of Yb3+-based NIR luminescence could be effectively prevented.

A series of mixed anion-induced Zn2Ln3 complexes [Zn2(L)3Cl2(μ2-OH)(μ3-OH)2Ln3(N3)2] (Ln = La, 1; Ln = Nd, 2; Ln = Yb, 3; Ln = Er, 4 or Ln = Gd, 5) have been obtained by the self-assembly of the precursor [Zn(L)(MeCN)] (H2L = N,N′-bis(3-methoxy-salicylidene)cyclohexane-1,2-diamine) with LnCl3·6H2O (Ln = La, Nd, Yb, Er or Gd) and NaN3 in alcohol-containing solutions. In these reactions, transmetallation of the partial precursor leads to the coexistence of two Zn2 + ions and one Ln3 + ion in the inner cis-N2O2 core and the other two Ln3 + ions in the outer O2O2 moieties of three deprotonated ligands. Photophysical studies suggest that the characteristic near-infrared (NIR) luminescence of Nd3 + and Yb3 + ions is sensitized through both the excited singlet 1LC and triplet 3LC states of the depronated ligand (L)2 −, despite the luminescent quenching with three OH− oscillators arround the Ln3 + ions.

A new semi-rigid tripodal ligand, namely 1,1′,1′′-((2,4,6-triethylbenzene-1,3,5 triyl)tris(methylene))tris(pyridin-4(1H)-one) (L1), has been prepared by direct alkylation of 4-hydroxypyridine at the nitrogen site with 1,3,5-tris(bromomethyl)-2,4,6-triethylbenzene. The tripodal ligand has been used for the assembly of a series of isomorphous lanthanide metal–organic frameworks (Ln-MOFs) [Ln(L1)·(NO3)3]·nH2O (Ln = Eu (1), Tb (2), Sm (3), Ce (4), Gd (5); n = 3 or 4) which exhibit an unusual non-interpenetrated (10,3)-d (or utp net) topology. The photophysical properties of these lanthanide MOFs have been assessed, in which the Tb3+ complex 2 displays bright green luminescence with quite high efficiency (Φoverall = 50%) and a long excited state lifetime (τobs = 1.1 ms).

Soil washing is one of the few permanent treatment alternatives for removing metal contaminants. Ethylenediaminetetraacetic acid (EDTA) and its salts can substantially increase heavy metal removal from contaminated soils and have been extensively studied for soil washing. However, EDTA has a poor utilization ratio due to its low selectivity resulting from the competition between soil major cations and trace metal ions for chelation. The present study evaluated the potential for soil washing using EDTA and three of its derivatives: CDTA (trans-1,2-cyclohexanediaminetetraacetic acid), BDTA (benzyldiaminetetraacetic acid), and PDTA (phenyldiaminetetraacetic acid), which contain a cylcohexane ring, a benzyl group, and a phenyl group, respectively. Titration results showed that PDTA had the highest stability constants for Cu(2+) and Ni(2+) and the highest overall selectivity for trace metals over major cations. Equilibrium batch experiments were conducted to evaluate the efficacy of the EDTA derivatives at extracting Cu(2+), Zn(2+), Ni(2+), Pb(2+), Ca(2+), and Fe(3+) from a contaminated soil. At pH 7.0, PDTA extracted 1.5 times more Cu(2+) than did EDTA, but only 75% as much Ca(2+). Although CDTA was a strong chelator of heavy metal ions, its overall selectivity was lower and comparable to that of EDTA. BDTA was the least effective extractant because its stability constants with heavy metals were low. PDTA is potentially a practical washing agent for soils contaminated with trace metals.

Three mercury complexes from a symmetric pentadentate ligand 2, 6-bis (8-quinolinyl thiomethyl) pyridine (L) have been prepared by the method of diffusing of diethyl ether or diisopropyl ether. The structures of the complexes have been identified by elemental analysis (EA), infrared spectra (IR) and single-crystal diffraction, and are composed of discrete mononuclear units in complexes 1 and 2 and binuclear units in complex 3. Especially, the valence of Hg in complex 3 is reduced to − 1 in-situ during self-assembly and Hg Hg σ bond is formed, which is further evidenced by the frontier orbital and natural bond orbital (NBO) properties calculated by DFT method. The antibacterial and antifungal activities of the ligand and the three complexes were also determined, which prove foundation information for research and application in pharmaceutical chemicals.

The robustly porous metal-organic framework MOF-Cu2I2(BTTP4) (BTTP4 = benzene-1,3,5-triyl triisonicotinate) was shown to work as an efficiently heterogeneous catalyst for the three-component coupling of sulfonyl azides, alkynes, and amines, leading to the formation of N-sulfonyl amidines in good yields. MOF-Cu2I2(BTTP4) can be recycled by simple filtration and reused at least four times without any loss in yield. Studies of the ligand effects on the three-component coupling reactions showed that BTTP4 could enhance the rate, as well as the chemoselectivity, when aromatic alkynes were employed. The catalytic process has been thoroughly studied by means of single-crystal and powder X-ray diffraction, gas and solvent adsorption, in situ (1)H NMR and FT-IR spectroscopy, X-ray photoelectron spectra (XPS), and ICP analysis of Cu leaching.

A reliable procedure for the synthesis of oxysulfonyl azides has been developed and applied to the three-component coupling reactions of azides, alkynes, and amines catalyzed homogeneously by CuI, which led to the formation of N-oxysulfonyl amidines with good yields. To fully evaluate the catalytic activity towards this coupling reaction, two coordination frameworks, namely, Cu2I2(PDIN) without micropores and Cu2I2(BTTP4) with micropores (PDIN=1,4-phenylene diisonicotinate, BTTP4=benzene-1,3,5-triyltriisonicotinate), were prepared by a facile one-pot reaction as heterogeneous catalysts. Catalytic results showed that nonporous Cu2I2(PDIN) was almost inactive for the three-component coupling reaction, whereas microporous Cu2I2(BTTP4) was an efficient heterogeneous catalyst for the synthesis of N-oxysulfonyl amidines. Furthermore, porous Cu2I2(BTTP4) displayed a shape-selective performance with respect to the alkyne substrates, and aromatic alkynes were preferable to aliphatic alkynes. The location of the catalytically active sites in the Cu2I2(BTTP4) framework has been studied by a series physical techniques, which includes powder XRD, CO2 gas adsorption, IR spectroscopy, energy dispersive X-ray analysis, and X-ray photoelectron spectroscopy, which suggests that the catalytic sites are not only on the external surface but also inside the micropores.

The coordination complexes of Ni(II) with the tripodal ligands tpta (tris[(1-phenyl-1H-1,2,3-triazol-4-yl)methyl]amine), tbta ([(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine), and tdta (tris[(1-(2,6-diisopropyl-phenyl)-1H-1,2,3-triazol-4-yl)methyl]amine) and the bidentate ligand pyta (1-(2,6-diisopropylphenyl)-4-(2-pyridyl)-1,2,3-triazole), [Ni(tpta)2](BF4)2 (1), [Ni(tbta)2](BF4)2 (2), [Ni(tdta)2](BF4)2 (3), and [Ni(pyta)3](BF4)2 (4), were synthesized from Ni(BF4)2·6H2O and the corresponding ligands. Complexes 2 and 4 were also characterized structurally using X-ray diffraction and magnetically via susceptibility measurements. Structural characterization of 2 that contains the potentially tetradentate, tripodal tbta ligand revealed that the Ni(II) center in that complex is in a distorted octahedral environment, being surrounded by two of the tripodal ligands. Each of those ligands coordinate to the Ni(II) center through the central amine nitrogen atom and two of the triazole nitrogen donors; the Ni-N(amine) distances being longer than Ni-N(triazole) distances. In case of 4, three of the bidentate ligands pyta bind to the Ni(II) center with the binding of the triazole nitrogen atoms being stronger than those of the pyridine. Temperature dependent susceptibility measurements on 2 and 4 revealed a room temperature χ(M)T value of 1.18 and 1.20 cm(3) K mol(-1), respectively, indicative of S = 1 systems. High-frequency and -field EPR (HFEPR) measurements were performed on all the complexes to accurately determine their g-tensors and the all-important zero-field splitting (zfs) parameters D and E. Interpretation of the optical d-d absorption spectra using ligand field theory revealed the B and Dq values for these complexes. Quantum chemical calculations based on the X-ray and DFT optimized geometries and their ligand field analysis have been used to characterize the metal-ligand bonding and its influence on the magnitude and sign of the zfs parameters. This is the first time that such extensive HFEPR, LFT, and advanced computational studies are being reported on a series of mononuclear, distorted octahedral Ni(II) complexes containing different kinds of nitrogen donating ligands in the same complex.

Three hydrogen-bonding frameworks based on N H⋯N and N H⋯O Hbond linkages have been synthesized and structurally characterized by using ntb (tris(2-benzimidazoylmethyl)amine) to react with two Cd(II) salts in the presence of dysfunctional bridging spacers of NaN3, 4'4-bipy and H2tpa (terephthalic acid) respectively. The building blocks of three complexes exhibit dumbbell-shape which stacks each other in the lattice leading to three 3D hydrogen-bonding frameworks with diversiform topology net of distorted NaCl net, (4,4) layer and 4 24 · 6 4 net.