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Two isostructural heterometallic ZrMOFs (denoted as ZrMOF-Co/Ni) were obtained by stepwise sysnthesis approach. Single-crystal X-ray structural analyses indicate that two ZrMOFs are both built from trinuclear zirconocene-based metallo-pyridine buliding blocks, featuring 2D infinite chain structure. Furthermore, the magnetic studies reveal that ZrMOF-Co shows antiferromagnetic performance, while ZrMOF-Ni feature ferromagnetic behavior.

Systematic design and self-assembly of metal-organic polyhedra with predictable configuration has been a long-standing challenge in crystal engineering due to the difficulty of finding suitable building units. Herein, we are focused on a concave polyoxovanadate cluster [V6O6(OCH3)9(SO4)4]5- that can be generated in situ under the exact reaction conditions. Based on this cluster, a potential trivalent molecular building block [V6O6(OCH3)9(SO4)(CO2)3]2- can be obtained by the bridging-ligand-substitution strategy that possesses appropriate angle information for the design of molecular cubes. Utilizing the face-directed assembly of the trivalent molecular building block and a diverse set of tetratopic carboxylate linkers, a series of metal-organic cubes VMOC-1 to VMOC-5 with the same topology but different functionalities and dimensions are designed and constructed. The inclusion study made with VMOC-3 as an example has shown that they are potential molecular receptors and can selectively capture size-matching polycyclic aromatic hydrocarbon guest molecules.

A rational synthetic strategy to construct two supramolecular isomers based on polyoxovanadate organic polyhedra with tetrahedral symmetries is presented. VMOP-α, a low-temperature product, has an extremely large cell volume (470 842 A3 ), which is one of the top three for well-defined MOPs. The corner-to-corner packing of tetrahedra leads to a quite low density of 0.174 g cm-3 with 1D channels (ca. 5.4 nm). The effective pore volume is up to 93.6 % of cell volume, nearly the largest found in MOPs. For the high-temperature outcome, VMOP-β, the cell volume is only 15 513 A3 . The packing mode of tetrahedra is corner-to-face, giving rise to a high-density architecture (1.324 g cm-3 ; channel 0.8 nm). Supramolecular structural transformation between VMOP-α and VMOP-β can be reversibly achieved by temperature-induced solvent-mediated transformation. These findings give a good opportunity for understanding 3D supramolecular aggregation and crystal growth based on large molecular tectonics.

Nanoscale regular polyhedra with icosahedral symmetry exist naturally as exemplified by virus capsids and fullerenes. Nevertheless, their generation by supramolecular chemistry through the linking of 5-fold symmetry vertices remains unmet because of the absence of 5-fold symmetry building blocks with the requisite geometric features. This situation contrasts with that of tetrahedral and octahedral symmetry metal–organic polyhedra (MOPs), for which appropriate triangular and square molecular building blocks (MBBs) that can serve as vertices or faces are readily available. Herein, we report isolation of a pentagonal [WV5O11(SO4)6]8– cluster and reveal its utility to afford the first four examples of nanoscale Goldberg MOPs, based upon 5-fold MBBs. Two 32-faced Gv(1,1) MOPs and two 42-faced Gv(2,0) MOPs were formed using linear or triangular organic ligands, respectively. The largest Goldberg MOP-4, exhibits a diameter of 4.3 nm, can trap fullerene C60 molecules in its interstitial cavities.

Reaction mechanism corresponding to reduction of NO to N2 by hydroxylammonium chloride (NH2OH⋅HCl) catalyzed by a ruthenium–substituted Keggin-type polyoxometalates (POMs) has been studied by using density functional theory (DFT) method with the M06L functional. A complete catalytic cycle including adsorption of reactant, activation of the hydroxylammonium chloride, formation of hyponitrous acid intermediates ((HNO)2), removal of water molecules to generate N2, has been proposed based on our mechanism study. The key intermediate (HNO)2 toward N2 is identified. The Ru center in this POM complex is proposed to be the active site, responsible not only for the formation of (HNO)2 by the reaction of NO and NH2OH⋅HCl but also for the subsequent two dehydration steps to form N2, which is well in agreement with available experimental literature. The calculated whole energy profiles indicate that the formation of dinitrogen is controlled by thermodynamic factor. Detailed electronic structure analysis indicates that the coordinated NO is a good electrophile and responsible for the catalytic activity because the Ru → NO+ back donating bonding interaction. These results provide a valuable insight to development of the redox catalyst of NO into inorganic POM field.

A novel metal-organic framework (MOF) with a π-conjugated porous condition is reported to sensor fused aromatic hydrocarbons molecules. This MOF assembled by N-heterocyclic multi-carboxyl ligands and Cd ions shows hexagonal hydrophobic channels along [100] and [010] directions with size 18.4 × 15.5 A2. Under the excitation of 338 nm, this MOF emits blue light peaking at 397 nm. Under immersing this MOF in the solutions containing aromatic hydrocarbon, including naphthalene, anthracene and phenanthrene within different time, the luminescent intensity of MOF enhanced different degree upon encapsulating aromatic hydrocarbons guest molecules. Therefore, this material shows favourable property of recognition for aromatic hydrocarbons molecules via solid-state photoluminescence.

Two Zr-based metal-organic cages (Zr-MOCs) were synthesized under solvothermal conditions. Directed by the solvent system, two Zr-MOCs that built from the same trinuclear zirconocene unit and 2,6-naphthalenedicarboxylic ligand (2,6-H2NDC) exhibit different geometry configurations. Zr-MOC-1 presents a tetrahedral cage structure, while Zr-MOC-2 features a capsule-like cage skeleton. The adsorption performances of Zr-MOCs for organic dyes from aqueous solution were first reported, which indicates that two Zr-MOCs show good adsorption behaviors for anionic and cationic dyes.

Unprecedented Anderson-like alkoxo-polyoxovanadate [V6O6(OCH3)9(μ6-SO4)(COO)3](2-) polyanions can serve as 3-connected second building units (SBUs) that assemble with dicarboxylate or tricarboxylate ligands to form a new family of metal organic tetrahedrons of V4E6 and V4F4 type (V = vertex, E = edge, and F = face). To our knowledge, this alkoxo-polyoxovanadate-based SBU is the first ever reported.

An unprecedented octavanadium-substituted polyoxoniobate Na18[Nb48V8(OH)30O130] · 33H2O (1), with a multiple-strand wheel structure, was successfully synthesized via a conventional aqueous method, which represents the largest vanadoniobate cluster reported to date. Single-crystal X-ray diffraction, ESI-MS spectrum, IR spectra, and UV-vis spectra were investigated. In addition, photocatalytic H2 evolution activity for 1 under UV light was observed with TEA as a sacrificial electron donor.

A unique three-dimensional metal azolate framework containing a tetranuclear copper cluster constructed by six 1,2,4-triazole units was synthesized in which the 1,2,4-triazole units show unusual bridging "crevice" coordination mode with their 1- and 2-positioned sp(2) N-atoms as symmetrically bridging centers. The photocatalytic activities of as-prepared compound were tested by degradation of rhodamine-B (RB) under different light irradiation.

Two unprecedented homochiral enantiomers based on two different kinds of rigid ligands, namely [Cd(NDC)L]2·H2O (1R and 1L), have been synthesized under hydrothermal conditions through spontaneous resolution. Their structures were determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR, and thermogravimetric (TG) analysis. The resulting framework 1, constructed by four kinds of homo-handed helical chains represents the first 3D self-penetrating framework formed by decoration of single (10,3)-a net with helical chains. The single (10,3)-a net in 1 formed by three kinds of different homo-handed helical chains is different from the standard one, which should be ascribed to the usage of V-shaped ligand L. A unique self-penetration motif can be discovered in 1 where one helical chain alternately passes through 10-membered shortest circuits linked to each other and in contrary, the corresponding circuits are bound to the helical chain. Interestingly, 1 exhibits fluorescent emission in both the solid and solution phase. The uncoordinated nitrogen atom and amino group from the triazole core on the crystal surface make it suitable to detect picric acid in water. The luminescence intensity of 1 in water can be efficiently quenched by the addition of picric acid (PA). The sensitive detection of PA can be continuously performed for at least five cycles without diminishing the fluorescence intensity and destroying the framework structure of 1. The possible quenching mechanisms for PA are also investigated.

Seven new coordination polymers, namely, [Zn(L)(bdc)]·2H2O (1), [Zn(L)(2-NH2-bdc)]·2H2O (2), [Zn(L)(bdc)]·1.75DMF·0.5H2O (3), [Zn(L)(oba)]·H2O (4), [Co(L)(oba)]·H2O (5), [Cd2(L)2(bdc)(NO3)2]·2DMF (6) and [Cd(L)(ndc)(H2O)] (7) (L = 4-amino-3,5-bis(4-imidazol-1-ylphenyl)-1,2,4-triazole, H2bdc = 1,4-benzenedicarboxylic acid, 2-NH2-H2bdc = 2-amino-1,4-benzenedicarboxylic acid, H2oba = 4,4′-oxydibenzoic acid and H2ndc = 1,4-naphthalenedicarboxylic acid), have been synthesized. The structures were determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR, and thermogravimetric (TG) analysis. 1 and 2 feature a similar three-fold interpenetrating network combined with interdigitation which extends the structure into a three-dimensional framework. 3 is a two-fold interpenetrating framework showing intralayer porosity and interdigitation. Compounds 1 and 3 represent a pair of supramolecular isomers where structural motifs and different interpenetration modes exist; compounds 4 and 5 are isostructural and display the same three-fold interpenetrating framework where two types of interlaced triple-stranded helices A and B can be found. The triple-stranded helices with opposite chirality for each type are distributed in adjacent layers. Compound 6 exhibiting a unique simultaneous threading fashion of adjacent polymeric motifs gives the novel (2D → 3D) polythreaded array where coordinated NO3− anions act as the dangling ligands. Compound 7 is a 6-connected 3D self-penetrating network where right- and left-handed single-stranded helical chains (AR and AL) and interlaced triple-stranded helices (BR and BL) coexist. The luminescence properties of compounds 1–7 were also measured and discussed.

A novel interpenetrating metal-organic framework, namely [Zn(3)L(2)(oba)(3)(H(2)O)(2)]·(4)H(2)O (1), has been synthesized under hydrothermal conditions. Its structure was determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR, and thermogravimetric (TG) analysis. In the structure of 1, the rigid and flexible V-shaped ligands link Zn(ii) to form a 3D structure where two types of helices and four types of pseudo-helical chains containing three pairs of enantiomers and two pairs of conformational isomers have been characterized. One such 3D framework incorporates six identical networks to form a 7-fold interpenetrated 3D framework. From the topological analysis, the Zn(ii) ions act as three- and four-connected nodes, and oba as well as L are linkers. The framework of compound can be classified as a new (6(3))2(6(5)·8) topology, which is a novel (3,3,4)-connected [4 + 3] 7-fold interpenetrating net showing 7-fold interlocking pseudo-helical chains and a unique catenane-like motif with Hopf links. In addition, the luminescence properties of the compound are discussed.

Two 2D isostructural organic–inorganic hybrid solid materials based on transition metal mono-substituted Keggin polyoxotungstate with an antenna molecule were synthesized under hydrothermal conditions. Compound 2 with the substituted Co(II) exhibits good photocatalytic activity in the degradation of rhodamine-B (RB) under visible light irradiation.

Two isostructural vanadium-based metal-organic polyhedra (denoted as VMOP-16 and VMOP-17) were synthesized by a solvothermal method, which are built from unprecedented {V

Three new polyoxovanadate-based metal-organic polyhedra (VMOPs) have been successfully synthesized and structurally characterized. Single crystals of three VMOPs were obtained by reaction of VCl3 and different carboxylate ligands (2,5-H2TDA = thiophene-2,5-dicarboxylic acid for VMOP-4, m-H2BDC = 1,3-benzenedicarboxylic acid for VMOP-5, 2,6-H2NDC = 2,6-naphthalenedicarboxylic aid for VMOP-6) under solvothermal conditions. Though all of the three hybrids feature the same {V(V)V4(IV)} units, their structures exhibit differences changing from truncated triangular prism to truncated quadrangular prism to octahedron, mainly depending on the nature of carboxylate ligands. Furthermore, the magnetic investigations reveal that VMOP-4-6 show similar ferromagnetic behaviors.

A tetra-Keggin polyoxometalate (POM), Cs19K2[Nb4O6(SiW9Nb3O40)4]Cl·27H2O (1) with a photocatalytic property has been synthesized by utilizing the self-assembly of W/Nb mixed-addendum POM [SiW9(NbO2)3O37]7 − under hydrothermal conditions. Its structure was determined by single-crystal X-ray diffraction, and further characterized by IR spectroscopy, thermogravimetric analysis, and cyclic voltammetry. Moreover, the photocatalytic activity of 1 for H2 evolution from water was observed under UV irradiation, suggesting that 1 might be a promising photocatalytic catalyst.

We have previously established a type of anti-resistant stealth liposomal topotecan plus amlodipine for overcoming the multi-drug resistance (MDR) in resistant leukemia cells. The objective of the present study was to further characterize it in the diversified non-resistant solid tumors in vitro and in vivo. Stealth liposomal topotecan plus amlodipine was re-prepared and physicochemically characterized. The in vitro drug release assays of topotecan and amlodipine from liposomes were performed using a dialysis method. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays were performed in murine sarcoma S180 cells and human breast cancer MCF-7 cells, respectively. Apoptotic percentages of S180 cells were evaluated using flow cytometry. In vivo anti-tumor activity study and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) analysis were performed in male Institute of Cancer Research (ICR) mice with S180 xenografts. Stealth liposomal topotecan plus amlodipine exhibited high drug encapsulation efficiencies, suitable particle size distribution, negatively charged zeta potential and prolonged release profiles for both topotecan and amlodipine. Amlodipine potentiated the antiproliferative effect and inducing apoptotic effect of topotecan on the tumor cells, exhibiting an additive anti-tumor effect. Stealth liposomal topotecan plus amlodipine showed the optimal anti-tumor activity and inducing apoptotic effect in the in vivo studies. Stealth liposomal topotecan plus amlodipine demonstrated an overt anti-tumor activity in non-resistant solid tumors, suggesting that it deserves further clinical evaluations.

The new compound Na18 [Nb48V8(OH)30O130] ·33H2O is synthesized by reaction of K7HNb6O19, VCl3, and NaOH (H2O, 70—75 °C, 5 h, 42% yield).

A novel 3D organic-inorganic hybrid framework constructed from tetra-Co(II)-substituted sandwich-type phosphotungstates with a rare 8-connected bcu topology is reported, which exhibited highly efficient photocatalysis activity under visible light and could be used for 5 cycles without any obvious decrease in activity.

A unique cationic metal–organic framework was synthesized by connecting the neutral rod-shaped secondary building unit with a cationic dicarboxylate ligand. This framework showed a rare snub square tessellation pattern by the periodic tiling of triangular and square nanotubes. The charge- and size-dependent ion-exchange of anion dyes was investigated.

The objectives of the present study were to define whether amlodipine induces apoptosis and what mechanism is involved in the process in human resistant and non-resistant leukemia cells following co-administration of stealth liposomal topotecan with amlodipine, a novel antiresistant liposomes developed by our institution. In three leukemias, K562, HL-60, and multidrug resistant (MDR) HL-60, cytotoxicity of topotecan was potentiated by amlodipine, while topotecan alone was resistant to MDR HL-60 cells. In two selected K562 or MDR HL-60 cells, the apoptotic effects were increased by addition of amlodipine, showing a dose-dependent manner. The activities of caspase 3 and 7 (marked as caspase 3/7), and caspase 8 were significantly activated by topotecan with amlodipine co-treated as the stealth liposomes. The deletions of intracellular Ca2+ stores induced by amlodipine correlated with the activated activities of caspase 3/7, or 8, respectively. In xenograft model with MDR HL-60 in nude mice, antitumor activity of stealth liposomal topotecan with amlodipine was significantly enhanced as compared to that of stealth liposomal topotecan or topotecan alone. In conclusion, apoptotic effect is associated with deletion of intracellular Ca2+ by amlodipine through activation of caspase 8 and then 3/7 activities. The enhanced antitumor activities by stealth liposomal topotecan with amlodipine are mainly due to the potentiating apoptotic effect and reversing the resistance by amlodipine. Stealth liposomal encapsulation of anticancer agent with a modulator may provide a novel strategy for improving the chemotherapeutic effects.

Cs19K2 [Nb4O6 (SiW9Nb3O40)4] Cl·27H2O is hydrothermally synthesized from a mixture of Cs8H[SiW9(NbO2)3O37], KCl, HCl, and H2O (autoclave, pH 2, 160 °C, 3 d, 76% yield).

The multi-drug resistance (MDR) could be caused by the over-expression of adenosine triphosphate binding cassette transporters such as p-glycoprotein, thereby resulting in the efflux of anti-cancer drugs from the cells. An anti-resistant stealthy liposomal vincristine plus quinacrine was defined in this study. Human chronic myelogenous leukemia K562 and MDR K562 cells were included for comparisons. Anti-tumor activity studies were performed on female BALB/c nude mice with MDR K562 cell xenografts. Results showed that quinacrine was effective in reversing the resistance in the MDR K562 cells, and enhanced the anti-tumor effect of vincristine in K562 cells. The caspase-9 and -3 activities in the MDR K562 and K562 cells were increased with the dose rise of quinacrine. In the MDR K562 cell xenografts in mice, the anti-resistant tumor effect of the stealthy liposomal vincristine plus quinacrine was evidently observed. The enhanced anti-tumor effects of vincristine by quinacrine in the resistant/non-resistant K562 cells could be because of the direct injury and the potentiating apoptotic effect of vincristine via activating the initiator caspase-9 and subsequently the effector caspase-3, and the long circulatory effect of stealthy liposomes. The stealthy liposomal encapsulation of vincristine plus quinacrine could be a potential therapeutic approach for resistant human leukemia.

Background Multidrug resistance (MDR) is a major obstacle to successful cancer chemotherapy as the over-expressed MDR protein acts as an efflux pump, which leads to a reduction in the uptake of the anticancer agent by tumour cells. We combined topotecan and amlodipine together into the stealthy liposomes, in which amlodipine was applied as a MDR reversing agent to overcome the resistance. Materials and methods Cytotoxicity, apoptosis and the signalling pathway assays were performed on human chronic myelogenous leukaemia K562, promyelocytic leukaemia HL-60 and MDR HL-60 cells, respectively. Pharmacokinetics and antitumour activity studies were performed on normal Kunming mice and female BALB/c nude mice with MDR HL-60 xenografts, respectively. Results Topotecan alone was effective in inhibiting the growth of non-resistant leukaemia cells, K562 and HL-60 cells but not the growth of MDR HL-60 cells. The resistance of topotecan in MDR HL-60 cells was potently reversed by the addition of amlodipine. Moreover, amlodipine enhanced the apoptosis-inducing effect of topotecan synergistically. Apoptosis was through activating caspases in a cascade: first, the initiator caspase 8 and then effectors caspase 3/7 (total activity of caspases 3 and 7) were activated. Being encapsulated into the stealthy liposmes with an acidic internal medium, topotecan existed dominantly in an active lactone species, which was reversibly changed from an inactive carboxylate form via a pH-dependent reaction. After administration of stealthy liposomes to mice, the blood exposure of the lactone form was evidently increased and extended. The antitumour effects in the MDR HL-60 xenografted tumour were stealthy liposomal topotecan (SLT) plus amlodipine > SLT > un-encapsulated topotecan > blank control. Conclusions The enhanced antitumour activity in the MDR HL-60 cells by the SLT plus amlodipine could be owing to multiple reasons: (a) synergistic apoptosis inducing effect, (b) reversing MDR by amlodipine and (c) increasing the availability of active lactone of topotecan by the stealthy liposomes. The apoptosis induced by amlodipine is through caspase 8 and then the 3/7 signalling pathway.

A new organic-inorganic hybrid titaniobate compound, [Cu(en)2][Cu(en)2(H2O)2]3[Ti2Nb8O28]·8H2O (1) (en = ethylenediamine), was successfully synthesized, characterized by single-crystal X-ray diffraction, IR spectroscopy, thermogravimetric analysis (TGA) and UV-Vis diffuse reflectance spectroscopy and its photoluminescence studied.