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TiO2 loaded with zinc oxide (ZnO/TiO2) catalysts were prepared and showed good catalytic performance of the transesterification of diphenyl carbonate (DPC) with 1,4-butanediol (BDO) to produce polycarbonate diol (PCDL).

A synthetic modulation approach has given rise to two topologically distinct thorium-based MOFs, whose polymorphism allows for elucidating how the structure of MOF, in isolation, influences the sensing efficacy of Cr(vi) oxyanions.

An unprecedented strategy to enhance iodine adsorption has been developed by post-synthetically installing electron-rich ligands into metal–organic frameworks.

In recent years, the treatment of dye wastewater has attracted widespread attention. Metal-organic frameworks (MOFs) adopt ordered porous structures and abundant active sites, which endorses them promising photocatalysts for the degradation of organic pollutants. In this work, two rare earth MOFs were successfully synthesized by solvothermal method from the reaction of of Eu3+ and Tb3+ salts with an aromatic tetracarboxylic acid H4TPTC (3,3',5,5'-terphenyl tetracarboxylic acid). X-ray single crystal diffraction indicated that the isostructural MOFs exhibited unique di-nuclear [Eu2(COO)4] or [Tb2(COO)4] clusters to construct three-dimensional coordination frameworks with solvent accessible channels along the [110] direction. These two MOFs had good thermal stability up to 400 °C and pH stability in the pH range of 3-9. The negative Zeta potential on the surface of these two complexes were conducive to the selective adsorption and degradation of cationic and neutral dyes, especially the high removal rate of large RhB molecules. For the photocatalytic degradation, mechanism studies showed that ·OH and ·O2- enhanced the sensitization of dyes and the separation of photogenerated carriers, and promoted the efficiency of photocatalytic degradation. This work provides two isomorphic rare earth MOFs adsorbents as well as photocatalysts for the purification of dye wastewater.

The synergistic assembly of uranyl cations and bppCOOH linkers gives rise to a UV and X-ray luminometric dosimeter with significantly enhanced sensitivity.

A brand-new application of thorium-bearing clusters in the field of ionizing radiation detection is exemplified by two novel hexanuclear thorium clusters, Th-bppCOO-1 and Th-bppCOO-2, which incorporate carboxylate-functionalized 2,6-di(pyrazol-1-yl)pyridine ligands. Notably, Th-bppCOO-1 is composed of an unprecedented [Th6(OH)4O4(H2O)5]12+ secondary building unit, the Th6 core of which is decorated by five H2O molecules. Furthermore, selective photoluminescence quenching responses of Th-bppCOO-1 and Th-bppCOO-2 toward X-ray over UV radiation have been demonstrated for the first time.

Polymorphism control of metal-organic frameworks is highly desired for elucidating structure-property relationships, but remains an empirical process and is usually done in a trial-and-error approach. We adopted the rarely used actinide cation Th4+ and a ditopic linker to construct a series of thorium-organic frameworks (TOFs) with a range of polymorphs. The extraordinary coordination versatility of Th4+ cations and clusters, coupled with synthetic modulation, gives five distinct phases, wherein the highest degree of interpenetration (threefold) and porosity (75.9 %) of TOFs have been achieved. Notably, the O atom on the capping site of the nine-coordinated Th4+ cation can function as a bridging unit to interconnect neighboring secondary building units (SBUs), affording topologies that are undocumented for other tetravalent-metal-containing MOFs. Furthermore, for the first time HCOOH has been demonstrated as a bridging unit of SBUs to further induce structural complexity. The resulting TOFs exhibit considerably different adsorption behaviors toward organic dyes, thus suggesting that TOFs represent an exceptional and promising platform for structure-property relationship study.

Synergistic assembly of uranyl centres and luminescent 2,6-bis(pyrazol-1-yl)pyridine-4-carboxylates (bppCOOH) gives rise to a uranyl coordination polymer, namely U-bppCOO, which exhibits a luminescence quenching response toward UV or X-ray irradiation doses. Notably, the photosensitivity of U-bppCOO has been significantly enhanced

A series of branched dodecyl phenol polyoxyethylene ethers (b-DPEOn) were successfully synthesized via alkylation and ethylene oxide addition reactions. The alkylation reaction was conducted by using a branched internal olefin as the raw material. Furthermore, the conversion rate of the branched dodecene was measured to be 98.1% and the selectivity towards branched dodecyl phenol (b-DP) was 95.9%. Moreover, b-DPEOn (b-DPEO7, b-DPEO10, b-DPEO12) were obtained via the reaction of ethylene oxide with b-DP. Notably, b-DPEO10 can efficiently reduce the surface tension of water below 31.55 mN m−1 at the critical micelle concentration (cmc) and the cmc value in water was approximately 1.3 × 10−2 g L−1 at 25 °C. The preferable wetting ability of b-DPEO10 was superior to that of commercialized dodecyl phenol polyoxyethylene ether (c-DPEOn), so it will be promoted and used in the textile and pesticide industries.

Expanding the family of lanthanide terpyridine coordination polymers has yielded eighteen new complexes with two different phases, Ln(TPC)2(HCOO)(H2O) (Ln-1) and Ln(TPC)(HCOO)2 (Ln-2) (Ln = Sm–Lu, except Tm). Both structures are composed of lanthanide cations interconnected by 2,2′:6′,2′′-terpyridine-4′-carboxylate ligands to yield one-dimensional chain topologies. However, the incorporation of an additional crystallographically unique decorative TPC ligand into Ln-1 gives rises to a distinct phase. The encapsulation of both metal- and ligand-based phosphors within single coordination polymers leads to dual-emission of the afforded materials. Furthermore, judicious lanthanide doping in heterometallic Ln-1 and Ln-2 allows for fine-tuning the photoluminescent colours over a wide range of gamut. Such a combination showcases the capability to fine-tune the emission colours from deep green, to red, and to blue. In addition, direct white-light emission upon UV excitation can be achieved in the SmxGd1−x-1 system.

Two POM-based copper coordination polymers constituted by Keggin-type polyoxometalates (POMs), [Cu2 (SiW12O40)2 (Fbtx)3 (H2O)4]n (1) and {[Cu2 (SiW12O40) (Fbtx)2 (H2O)2.75]·4.5H2O}n (2) (Fbtx = 2,3,5,6-tetrafluoro-1,4-bis (1,2,4-triazole-1-ylmethyl)benenze) have been hydrothermally synthesized by the same precursor at different pH values and structurally characterized by single-crystal X-ray diffraction, powder X-ray diffraction, element analyses and IR. Both of them have two-dimensional coordination layers constructed by bidentate SiW12O404− anions and bridging Fbtx ligands, in which complex 1 exhibits a 2D + 2D → 2D interpenetrated network with sql topology, while complex 2 features a binodal 3,5-connected network bearing new topology with a Schlafli symbol of {44;66}{62;10}. Additionally, the thermal stability, fluorescent properties and photocatalytic properties of complexes 1 and 2 have also been investigated. The results indicate that complexes 1 and 2 can serve as recyclable heterogeneous photocatalysts and show good catalytic activity for the degradation of Rhodamine B under UV irradiation.

Microwave-assisted hydrothermal reaction of 2-fluoro-3,5,6-tri(1H-1,2,4-triazol-1-yl)-1,4-benzenedicarbonitrile (L1) with silver(I) nitrate yields a coordination polymer [Ag3(L2)2(NO3)] n (1), in which the L2 ligand (HL2 = 2-hydroxy-3,5,6-tri(1H-1,2,4-triazol-1-yl)terephthalonitrile) is obtained by in situ ligand transformation from the L1 precursor. HL2 monohydrate has also been isolated by the microwave-mediated hydrolysis of L1 and structurally characterized. Single-crystal X-ray diffraction reveals that HL2 monohydrate comprises a zwitterionic HL2 moiety, while complex 1 displays an infinite L2-bridged double-chain structure. Given that the HL2 molecule has a large conjugated π system, complex 1 exhibits strong blue luminescence in the solid state at room temperature.

Effective disposal of radioactive iodine has been a persistent challenge in nuclear fuel recycling. Herein, we synthesized a series of micro-/mesoporous hierarchical adsorbents by the zeolitic imid...

The ring-opening polymerization (ROP) of cyclic esters/carbonates is a crucial approach for the synthesis of biocompatible and biodegradable polyesters. Even though numerous efficient ROP catalysts have been well established, their toxicity heavily limits the biomedical applications of polyester products. To solve the toxicity issues relating to ROP catalysts, we report herein a biocompatible coordination network, CZU-1, consisting of Zn4(μ4-O)(COO)6 secondary building units (SBUs), biomedicine-relevant organic linkers and guest water, which demonstrates high potential for use in the catalytic ROP synthesis of biomedicine-applicable polyesters. Both experimental and computational results reveal that the guest water in CZU-1 plays crucial roles in the activation of the Zn4(μ4-O)(COO)6 SBUs by generating μ4-OH Brønsted acid centers and Zn–OH Lewis acid centers, having a synergistic effect on the catalytic ROP of cyclic esters. Different to the mechanism reported in the literature, we propose a new reaction pathway for the catalytic ROP reaction, which has been confirmed using density functional theory (DFT) calculations, in situ diffuse reflectance IR Fourier transform spectroscopy (DRIFTS), and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS). Additionally, the hydroxyl end groups allow the polyester products to be easily post-modified with different functional moieties to tune their properties for practical applications. We particularly expect that the proposed catalytic ROP mechanism and the developed catalyst design principle will be generally applicable for the controlled synthesis of biomedicine-applicable polymeric materials., A new ring-opening polymerization mechanism is unveiled based on synergistic catalysis involving Brønsted and Lewis acid centers in a coordination framework.

By introducing alkaline-earth metal ions (Mg2+, Ca2+, and Sr2+) as structure-directing agents, three new heterometallic complexes, Mg(H2O)6·[Cu2Mg(L)4(H2O)4]·4H2O (1), [CuCa(L)2(H2O)4]n (2) and [CuSr(L)2(H2O)4]n (3) [H2L = 4-(3-(pyridine-4-yl)-1H-1,2,4-triazol-5-yl)picolinic acid], have been synthesized under hydrothermal conditions and structurally characterized. H2L was in situ generated from hydrolysis of the well-known selective xanthine oxidase inhibitor topiroxostat. Complex 1 crystallizes in the space group P21/c and exhibits a zero-dimensional (0-D) structure containing the discrete [Mg(H2O)6]2+ cationic and [Cu2Mg(L)4(H2O)4]2– dianionic moieties. Complexes 2 and 3 are isostructural and crystallize in the space group C2/c, with one-dimensional (1-D) polymeric structure with infinite Cu(II)–Ca/Sr–carboxylate chains. The results reveal the significant influence of the alkaline-earth metal ions on the molecular structure. Their spectroscopic, thermal and solid-state luminescent properties have also been investigated.

By utilizing a flexible fluorinated bis(triazole) ligand 1,4-bis(1,2,4-triazole-1-ylmethyl)-2,3,5,6-tetrafluorobenzene (Fbtx), a thermally and chemically stable cobalt(II)-containing tungstovanadate-based metal–organic framework (MOF) {[Co3(Fbtx)5(V2W18O62)(H2O)2]·26H2O}n (denoted as CZU-5) was synthesized and structurally characterized. The X-ray structural analysis revealed that CZU-5 features a three-dimensional (3-D) self-penetrated α-polonium cubic structure, which results from a 3-D 4-fold interpenetrated diamondoid [Co(Fbtx)]n network connected by the Wells–Dawson-type tungstovanadate clusters. Unexpectedly, the introduction of vanadium atoms as heteroatoms into the Dawson-type anion in polyoxometalate (POM)-based coordination polymers has not been reported to date. For the first time, the POM-based material was demonstrated to be an effective catalyst for the solvent-free ring-opening polymerization of e-caprolactone. Moreover, the CZU-5 catalyst could be recycled up to five times with the retention of both catalytic activity and crystal structure.

The microwave heating hydrothermal and solvothermal reactions (120 °C, 20 min) of a new rigid tris-triazole ligand, 2-fluoro-3,5,6-tri(1H-1,2,4-triazol-1-yl)-1,4-benzenedicarbonitrile, with Zn(II), Cd(II) and Pb(II) metal salts afforded four crystalline coordination polymers (CPs), namely, {[Zn(L)2(H2O)2]·2H2O}n (1), {[Cd(L)2(H2O)2]·2H2O}n (2), {[Cd(L)(NO3)(DMF)]·0.5DMF·0.25CH3CN}n (3) and {[Pb(L)2(H2O)2]·H2O}n (4), respectively, where the starting ligand undergoes in situ hydrolysis to form a new ligand 2-oxidanyl-3,5,6-tri(1H-1,2,4-triazol-1-yl)terephthalonitrile (HL). Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction, and thermogravimetric (TG) analyses. Both complexes 1 and 2 are isostructural, featuring 1-D looped-chain structures. Complex 3 displays a 2-D 44-sql layer structure, while complex 4 presents a 3,6-connected 3-D framework with an anatase topology. The remarkable structural diversity of complexes 1–4 may illustrate the powerful effect of metal ions and solvent systems in coordination assemblies. Furthermore, since HL is a rigid ligand with the large conjugated π-system, all these complexes exhibit strong blue luminescence emissions in the solid state at room temperature.

Based on the acid-base mixed-ligand assembly strategy, a stable Mn(II)-based metal-organic framework (denoted as Mn-MOFs), containing 1-D Mn–O–C rod-shaped chains, was hydrothermally synthesized and structurally characterized. This material was demonstrated to be an efficient heterogeneous catalyst for the decarboxylative sulfonylation of cinnamic acids with sodium benzene sulfinates. Moreover, the Mn-MOF catalyst could be recycled up to six times with the retention of both catalytic activity and crystal structure.

Phenol is commercially produced through cumene hydroperoxide (CHP) cleavage in kettle reactor, having the disadvantages of hazard potential, low selectivity, low efficiency and complicated process. In the study, microchannel reactor has been introduced into the decomposition using sulfuric acid as the catalyst. The influences of various reaction conditions, including temperature, the ratio of sulfuric acid/CHP and residence time, on the reaction have been studied. Compared with kettle reactor, the present process can afford almost quantitative yield of phenol with reduced acid amount and shortened reaction time under higher reaction temperature. The microchannel process can also provide higher security of CHP cleavage. The microtechnology probably gives an alternative protocol for the production of phenol through CHP decomposition. In addition, the possible main reaction pathways for the CHP cleavage in microchannel reactor have been discussed according to the obtained results.

Some metalloporphyrins (MTPPs, M = Ni, Fe, Co, and Cu) have been introduced as catalysts for the dehydrogenative aromatization of hydrocarbons using molecular oxygen as the ultimate oxidant. The results revealed that NiTPP could efficiently catalyze the dehydroaromatization of 9,10-dihydroanthracene by O2 to anthracene, and various substrates could be tolerated. According to the obtained results, a possible reaction pathway for the aerobic dehydrogenative aromatization of hydrocarbons under nickel porphyrin has been proposed.

The rational design and synthesis of metal-organic frameworks with well-controlled interpenetration have been active research areas of inquiry, particularly for porosity-related applications. Herein, we extend the use of the ligand steric modulation strategy to initiate the first study of the interpenetration control of thorium-based MOFs. The approximate "hardness" of the Th4+ cation, which was conjugated with aromatic substitutions and delicately modified synthetic conditions, allows for the crystallization of single crystals of seven new Th-MOFs with five distinct topologies. Solvothermal reactions of Th(NO3)4 with the triphenyl H2TPDC ligand under variable conditions exclusively gave rise to an interpenetrated Th-MOF with a hex topology, namely Th-SINAP-16. Modifications of the ligand sterics with two pendant methyl groups to 2',5'-Me2TPDC2- and 2,2″-Me2TPDC2- afforded two noninterpenetrated UiO-68-type Th-MOFs (Th-SINAP-17 and Th-SINAP-20, respectively) with record-high pore volumes (74.8% and 75.3%, respectively) among all the thorium MOFs. Moreover, another four Th-MOFs Th-SINAP-n (n = 18, 19, 21, and 22) with three different topologies were obtained by a simple synthetic modulation. Notably, Th-SINAP-16 and Th-SINAP-21 represent the second rare examples of interpenetrated Th-MOFs reported to date. These findings revealed the unprecedented structural complexity and synthetic accessibility of Th-MOFs among all tetravalent metal containing MOFs. Such features make Th-MOFs as an ideal platform to elucidate the structure-property relationship for various applications, e.g. iodine adsorption.

Single-crystal-to-single-crystal transformation of metal–organic frameworks has been met with great interest, as it allows for the creation of new materials in a stepwise manner and direct visualization of structural transitions when subjected to external stimuli. However, it remains a peculiarity among numerous metal–organic frameworks, particularly for the ones constructed from tetravalent metal cations. Herein, we present a cationic thorium–organic framework displaying unprecedented triple single-crystal-to-single-crystal transformations in organic solvents, water, and NaIO3 solution. Notably, both the interpenetration conversion and topological change driven by the SC–SC transformation have remained elusive for thorium–organic frameworks. Moreover, the single-crystal-to-single-crystal transition in NaIO3 solution can efficiently and selectively turn the ligand-based emission off, leading to the lowest limit of detection (0.107 μg kg−1) of iodate, one of the primary species of long-lived fission product 129I in aqueous medium, among all luminescent sensors., A cationic thorium–organic framework displaying unprecedented triple single-crystal-to-single-crystal transformations has been developed, allowing for ultrasensitive and selective sensing of iodate.

ObjectivesOrganotropism is primarily determined by tumor-derived exosomes. To date, the role of lung cancer cells-derived exosomes underlying the pre-metastatic niche formation is unclear.Materials and MethodsThe animal models of retro-orbital and intra-ventricular injection were constructed to administrate lung cancer cells-derived exosomes. Cytokine array was used to screen the cytokines released from brain endothelium after internalization of lung cancer cells-derived exosomes. The cellular co-culture system was established to mimic microglia-vascular niche contained lung cancer cells-derived exosomes. The levels of Dkk-1 and the activities of microglia were analyzed by qRT-PCR, western blot and immunofluorescence. In vivo selections of highly brain metastatic cells were performed to analyze the direct interaction of lung cancer cells with microglia.ResultsAnimal studies demonstrated that there was a suppressive signal transferred from brain endothelium to microglia after internalization of lung cancer cells-derived exosomes into brain endothelium, which caused an absolutely less M1 phenotypic microglia and a relatively more M2 phenotypic microglia. Further results indicated that lung cancer cells-derived exosomes induced a release of endogenous Dkk-1 from brain endothelium, which rendered microglia to acquire a pro-tumorigenic feature in pre-metastatic niche. Subsequently, the declines of Dkk-1 in metastatic lung cancer cells removed the suppression on microglia and enhanced microglial activation in metastatic niche.ConclusionOur findings shed a new light on the synergistic reaction of the different cells in “neurovascular units” toward the metastatic messages from lung cancer cells and provided a potential therapeutic pathway for lung cancer metastasis to brain.

The mixed-ligand strategy is one of the important methods for preparing new materials and regulating the properties of materials. In this work, by introducing different auxiliary ligands (ALs), we have obtained a series of mixed-ligand uranyl complexes (1-6) from a flexible biphenyltetracarboxylic acid (H4bptc) with an adjustable orthogonal conformation and studied the influence of different organic base molecules on the coordination and assembly of H4bptc with a uranyl cation. It is found that the coordinated ALs, including 4,4'-bipyridine-1,1'-dioxide and 1,10-phenanthroline, partially occupy the coordination sites of the uranyl center and directly affect the molecular conformations and uranyl coordination of flexible bptc linkers. On the other hand, noncoordinated ALs such as protonated 4,4'-bipyridine ([H2(4,4'-bpy)]2+) or dimethylammonium, which work as counterions in the form of encapsulated guests or hydrogen-bonded templates, also have a nonnegligible impact on the conformation and coordination of bptc linkers. Most interestingly, the AL-mediated evolution of uranyl coordination by the bptc linker and coordination geometry of the uranyl center is clearly observed, which suggests the adaptability of flexible bptc linkers to take suitable molecular configurations and uranyl coordination modes so as to adapt to the external regulator agents and varying environment. The physicochemical characterization of these uranyl compounds, especially photoluminescence, is addressed and discussed, and the results reveal that compound 5 has the potential to serve as a multifunctional radiation detection material for UV light and X-ray radiation.

Effective capture of radioactive iodine is of paramount importance for the safe and long-term storage of fission products in the nuclear fuel cycle. Herein, a series of functionalized Th-UiO-66 MOFs was employed as a model to investigate the effects of substituents on iodine adsorption in both solution and vapor states. Sorption studies revealed that the electro-donating amino group exhibits the most positive role on increasing the removal rate of iodine from cyclohexane and the uptake capacity of iodine vapor. Particularly, the disubstituted Th-UiO-66-(NH2 )2 can effectively remove 91.9 % of iodine (300 mg L-1 ) from cyclohexane and capture 969 mg g-1 iodine vapor, significantly higher than 59.6 % and 334 mg g-1 of untagged Th-UiO-66, respectively. In addition, the substituent effect on the radiolytic stability of MOFs was for the first time investigated, leading to the unearthing of one of the most radioresistant MOFs Th-UiO-66-NH2 reported to date.

High-level ab initio computations have been performed to investigate molecular structures, potential energy curves, vibrational energy levels and spectroscopic constants for twelve Λ-S states of the first four dissociation limits of MgBi. Characterizations of seven Ω states, corresponding to the first and the second Λ-S dissociation limits, have been explored for the first time. The spin–orbit coupling effect is revealed to have introduced a significant impact on the pattern of these electronic states and interactions among them. Our predictions for molecular structures and spectroscopic constants of MgBi are compared with available data of other magnesium-group 18 family species. Regular tendencies of these parameters are clearly exhibited when the group 18 atom is replaced by another one in the group. Information associated with transition dipole moments, Franck-Condon factors, vibrational branching ratios and radiative lifetimes between the Ω states are obtained and their transitional properties are analyzed and discussed. The results and data determined in this work are expected to guide and assist laboratorial detections of MgBi and to extend our understanding for the magnesium-group 18 species.

Although metal-organic frameworks (MOFs) have been reported as important porous materials for the potential utility in metal ion separation, coordinating the functionality, structure, and component of MOFs remains a great challenge. Herein, a series of anionic rare earth MOFs (RE-MOFs) were synthesized via a solvothermal template reaction and for the first time explored for uranium(VI) capture from an acidic medium. The unusually high extraction capacity of UO22+ (e.g., 538 mg U per g of Y-MOF) was achieved through ion-exchange with the concomitant release of Me2NH2+, during which the uranium(VI) extraction in the series of isostructural RE-MOFs was found to be highly sensitive to the ionic radii of the metal nodes. That is, the uranium(VI) adsorption capacities continuously increased as the ionic radii decreased. In-depth mechanism insight was obtained from molecular dynamics simulations, suggesting that both the accessible pore volume of the MOFs and hydrogen-bonding interactions contribute to the strong periodic tendency of uranium(VI) extraction.

A Rh (III)−catalyzed synthesis of isoquinoline derivatives from N-hydroxyoximes and alkynes via C–H activation/annulation process in biomass-derived γ-valerolactone (GVL) has been developed. A series of functional groups were well tolerated, affording the desired products in good to excellent yields.

A new zinc(II)-based coordination polymer {[Zn(5-fip)(tdbpy)]·(DMF)} n (1) {5-H2fip=5-fluoroisophthalic acid, tdbpy=4,4′-(2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl)bispyridine, DMF=dimethylformamide} has been solvothermally synthesized and structurally characterized. Single-crystal X-ray diffraction revealed that complex 1 shows a unique two-dimensional network architecture containing single-stranded [Zn(5-fip)] n and double-stranded helical [Zn(tdbpy)] n chains. The thermal and luminescence properties of complex 1 have also been studied.