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Herein we report a discrete heterometallic Pd 4 Cu 8 L 8 cage with a tubular structure, which was synthesized by the assembly of copper metalloligands and Pd II ions in a stepwise manner. The Pd 4 Cu 8 L 8 cage has been unequivocally characterized by single-crystal X-ray diffraction, electrospray ionization-mass spectroscopy, and energy dispersive spectroscopy. The cage showed excellent catalytic activity in the epoxidation of styrene and its derivatives under conditions without using additional solvent, providing potential material for catalyzing the oxidation reactions.

When compared to industrially stable zeolites, the instability of metal-organic frameworks (MOFs) has been denounced by researchers. Boosting the stability of existing MOFs is highly important for practical applications. In this report, we develop a new strategy to prepare MOFs/poly(tetrafluoroethylene) (PTFE) composites, which can highly improve the chemical, pressure, and photostabilities of zeolitic imidazolate framework (ZIF)-8. Composite materials were prepared by a physical blending of ZIF-8 and PTFE emulsion with different ratios and annealing at 370 °C. Transmission electron microscopy (TEM) studies reveal that the nanoparticles of ZIF-8 are coated by PTFE to form the composite materials. Upon mixing with 20 or 50 wt % PTFE, the ZIF-8/PTFE materials show a superhydrophobic property with water contact angles of around 156°. Pristine ZIF-8 is not stable in water with stirring under acidic, basic, and irradiation conditions, while the ZIF-8/PTFE materials are stable under the same conditions. The ZIF-8/PTFE materials can also maintain their crystalline structure after being compressed with a 10 MPa pressure, while pristine ZIF-8 changes to an amorphous solid after the same pressure treatment. Using water as a solvent, ZIF-8/PTFE can be used as a highly efficient and recyclable catalyst for Knoevenagel reaction at room temperature. The successful preparation of stable ZIF-8/PTFE composite materials provides a useful method to enhance the chemical, pressure, and photostabilities of MOFs.

Metal-organic cages, a class of supramolecular containers constructed by the self-assembly of metal ions and organic ligands, show great promise as catalytic agents. In this work, we designed and synthesized a series of rhombic dodecahedral Ni-Cu heterometal imidazolate cages (Ni 8 Cu 6 L 24 ) that can act as highly active photo-Fenton-like catalysts. These cages possess a high ability to generate hydroxyl radicals ( • OH) under visible light in the presence of H 2 O 2 , which can rapidly degrade organic pollutants (e.g., rhodamine B, methylene blue, and methyl orange) into CO 2 and H 2 O. Besides, they are robust catalysts, with high catalytic activity and reusability under conditions in high H 2 O 2 concentration, providing potentially advanced materials for degrading persistent organic pollutants.

Water oxidation to molecular oxygen is indispensable but a challenge for splitting H 2 O. In this work, a series of Co-based metal-organic cages (MOCs) for photoinduced water oxidation were prepared. MOC-1 with both bis(μ-oxo) bridged dicobalt and Co-O (O from H 2 O) displays catalytic activity with an initial oxygen evolution rate of 80.4 mmol/g/h and a TOF of 7.49 × 10 -3 s -1 in 10 min. In contrast, MOC-2 containing only Co-O (O from H 2 O) in the structure results in a lower oxygen evolution rate (40.8 mmol/g/h, 4.78 × 10 -3 s -1 ), while the amount of oxygen evolved from the solution of MOC-4 without both active sites is undetectable. Isotope experiments with or without H 2 18 O as the reactant successfully demonstrate that the molecular oxygen was produced from water oxidation. Photophysical and electrochemical studies reveal that photoinduced water oxidation initializes via electron transfer from the excited [Ru(bpy) 3 ] 2+ * to Na 2 S 2 O 8 , and then, the cobalt active sites further donate electrons to the oxidized [Ru(bpy) 3 ] 3+ to drive water oxidation. This proof-of-concept study indicates that MOCs can work as potential efficient catalysts for photoinduced water oxidation.

The SiF 6 2- anions are in situ formed in the reactions of MF 2 (M = Cu 2+ , Zn 2+ , Ni 2+ , and Co 2+ ) salts and nitrogen-containing ligands in borosilicate glass tubes under solvothermal conditions and then used to further construct a family of metal-organic frameworks (MOFs). This in situ reaction demonstrates a new and facile strategy for the fabrication of MOFs based on SiF 6 2- .

Using water as the sole solvent, the bifunctional molecule tetrakis(methylthio)-1,4-benzenedicarboxylic acid (TMBD) was reacted with Cu(CH 3 CN) 4 BF 4 to form a robust microporous metal-organic framework (MOF, CityU-7) featuring Cu(I) ions being simultaneously bonded to the carboxyl and thioether donors. The MOF solid is stable in air and can be easily activated by heating, without the need for treatment with organic solvents. The subnanoscopic pores (ca. 0.6 nm) of the host net allow for uptake of CO 2 and H 2 O but exhibit lesser sorption for N 2 at 77 K. The microporous net can also be penetrated by I 2 molecules.

Three coordination polymers (CPs) with square-planar Cu II /Ni II N 4 subunits were formed in one step by subcomponent self-assembly, giving rise to an unprecedented linking variety of in situ embedded metalloligands and Cu I clusters. All CPs exhibit unusual visible-light adsorption. Enhanced photocatalytic activity and high selectivity were observed in the oxidation of benzene under visible-light irradiation.

A series of Ni-imidazolate cubic cages, one-dimensional and two-dimensional coordination polymers based on the cubic cages, have been prepared by solvothermal subcomponent self-assembly of 5-methyl-4-formylimidazole, m-xylylenediamine, and Ni(II) salts with varied anions. These compounds have been characterized by single-crystal X-ray diffractions, elemental analysis, IR spectra, and powder X-ray diffractions. The formation of an oligomerized coordination cage or an infinite coordination polymer depends on the anions chosen. An oligomerized 8-nuclear Ni-imidazolate cubic cage is formed when the anion Cl(-), Br(-), I(-), SCN(-), NO2(-), or NO3(-) is utilized in the reactions, and a two-dimensional coordination polymer based on the Ni-imidazolate cubic cage will be obtained when N3(-), (CN)2N(-), or (CN)3C(-) act as the anions. When only ClO4(-) or both ClO4(-) and [Ni(C4N2S2)2](2-) (C4N2S2 = dimercaptomaleonitrile) as anions exist in the reaction mixture, a ladder-like one-dimensional coordination polymer based on the Ni-imidazolate cubic cage and formate is formed unpredictably.

Glucose monitoring with high sensitivity and accuracy in the cerebrospinal fluid is a challenge for evaluating the role of glucose in the physiological and pathological processes. In this work, a ratiometric fluorescent probe for sensing glucose was developed. In the probe, the gold nanoclusters protected by ovalbumin played the role as the reference of fluorophore and the Alizarin Red S-3-aminophenyl boronic acid immobilized on the poly(N-acryloxysuccinimide) acted as both the response signal and specific recognition unit for sensing glucose. Once the ratiometric fluorescent probe reacted with glucose in the biological system, its fluorescence intensity at 567 nm was quenched, while the fluorescence intensity at 610 nm was essentially unchanged. In addition, the prepared ratiometric fluorescent probe showed higher stability against environmental effects. As a result, the present ratiometric fluorescent probe was successfully used for monitoring of glucose in the rat brain following the cerebral calm/ischemia.

A series of neutral cubic nickel(II)-imidazolate Ni8L12X4 cages were prepared by rational choices of substituents and anions with solvothermal subcomponent self-assembly technology. Both substituents and halide anions play a critical role in the formation and stabilization of cubic cages. Changing one of the factors in the reaction will switch the final structure to a Ni14L24 rhombic dodecahedral cage. The cubic cage can transform to a large rhombic dodecahedral cage in the presence of methylamine at room temperature accompanied by a color change from purple to light yellow.

Inorganic copper(I)/silver(I) halide/pseudohalide components are used to thread classical organic tetracationic macrocycles, cyclobis(paraquat-p-phenylene) and cyclobis(paraquat-4,4'-biphenylene), to construct crystalline inorganic-organic adducts, featuring an unprecedented hybrid polyrotaxane and several unusual hybrid pseudorotaxanes and sandwiches.

Artificial molecular architecture from a large number of subcomponents (>50) via self-assembly remains a formidable challenge for chemists. Reaction of 38 components [14 Ni(2+) and 24 N-methyl-1-(4-imidazolyl)methanimine] under solvothermal conditions reproducibly leads to the formation of a high-symmetry coordination cage. This polyhedral cage can also be obtained in high yield by self-assembly of 62 commercially available subcomponents (24 methylamine, 24 4-formylimidazole, and 14 Ni(2+)) under mild conditions involving synchronized formation of both dynamic covalent bonds and coordination bonds. Guest molecules (e.g., water, methylamine, and methanol) are randomly imprisoned in the cage.

The gyroid is ubiquitous for underlying the construction of natural substance and artificial zeolites, but it has been, surprisingly, overlooked by chemists who work in the field of metal-organic frameworks (MOFs). In this work, a series of gyroidal MOFs with gie topology, constructed from 1,2-bis((5H-imidazol-4-yl)methylene)hydrazine and octahedral metal ions, such as Zn(II), Mn(II), Cu(II), and Ni(II), have been synthesized. The Zn(II) analogue, named as STU-1, shows exceptional thermal and chemical stabilities, and exhibits permanent porosity and CO(2) capture ability., (© 2011 American Chemical Society)

By systematically varying the geometric length and electronic properties of the second ligating ligands of halogen (Cl(-), Br(-), and I(-)) and pseudohalogen (CN(-), SCN(-), and N(3)(-)) anions, we synthesized 11 isomeric/isostructural copper(I) complexes: [Cu(2)(L3-3)I](n) (1), [Cu(2)(L4-4)Br](n) (2-Br), [Cu(2)(L4-4)Cl](n) (2-Cl), [Cu(2)(L3-4)(CN)](n) (3), [Cu(2)(L3-3)(CN)](n) (4), [Cu(3)(L4-4)(CN)(2)](n) (5), {[Cu(2)(L4-4)Br](2)·CuBr}(n) (6-Br), {[Cu(2)(L4-4)Cl](2)·CuCl}(n) (6-Cl), [Cu(2)(L4-4)(SCN)](n) (7α-SCN), [Cu(2)(L4-4)(SCN)](n) (7β-SCN), and [Cu(2)(L4-4)(N(3))](n) (7α-N(3)). These structures are based on a series of isomeric pyridylpyrazole ligands, namely, 3,5-bis(3-pyridyl)-1H-pyrazole (HL3-3), 3-(3-pyridyl)-5-(4-pyridyl)-1H-pyrazole (HL3-4), and 3,5-bis(4-pyridyl)-1H-pyrazole (HL4-4), and their structural features range from 1-D (1), 2-D (2), and 3-D noninterpenetration (3), to 3-D 2-fold interpenetration (4 and 5), to 3-D self-catenation (6 and 7), exhibiting a trend from simple to complex with dimension expansion and an interpenetrating degree increase. The five most complex structures (6 and 7) with self-catenated networks are based on 2-fold interpenetrated networks linked via appropriate second ligating spacers (Cl(-), Br(-), SCN(-), and N(3)(-)), representing a strategy to construct self-catenated coordination polymers through cross-linking interpenetrated frameworks. Moreover, these complexes exhibit strong photoluminescence, which is mainly ascribed to Cu(I)-related charge transfers (MLCT, MC, and MMLCT) regulated by the electronic properties of halogen or pseudohalogen. The topological evolution and luminescence variation presented in this work open an avenue to understanding the luminescence origin and the structure-property relationship of luminescent coordination polymers.

We report dynamic, multiple single-crystal to single-crystal transformations of a coordination network system based on a semirigid molecule, TCPSB = 1,3,5-tri(4'-carboxyphenylsulphonyl)benzene, which nicely balances shape persistence and flexibility to bring about the framework dynamics in the solid state. The networks here generally consist of (1) the persistent core component (denoted as CoTCPSB) of linear Co(II) aqua clusters (Co-O-Co-O-Co) integrated into 2D grids by 4,4'-bipyridine and TCPSB and (2) ancillary ligands (AL) on the two terminal Co(II) ions-these include DMF (N,N'-dimethylformamide), DMA (N,N'-dimethylacetamide), CH(3)CN, and water. Most notably, the ancillary ligand sites are highly variable and undergo multiple substitution sequences while maintaining the solid reactants/products as single-crystals amenable to X-ray structure determinations. For example, when immersed in CH(3)CN, the AL of an as-made single crystal of CoTCPSB-DMF (i.e., DMF being the AL) is replaced to form CoTCPSB-CH(3)CN, which, in air, readily loses CH(3)CN to form CoTCPSB-H(2)O; the CoTCPSB-H(2)O single crystals, when placed in DMF, give back CoTCPSB-DMF in single-crystal form. Other selective, dynamic exchanges include the following: CoTCPSB-DMF reacts with CH(3)CN (to form CoTCPSB-CH(3)CN) but NOT with water, methanol, ethanol, DMA, or pyridine; CoTCPSB-H(2)O specifically pick outs DMF from a mixture of DMF, DMA, and DEF; an amorphous, dehydrated solid from CoTCPSB-H(2)O regains crystalline order simply by immersion in DMF (to form CoTCPSB-DMF). Further exploration with functional, semirigid ligands like TCPSB shall continue to uncover a wider array of advanced dynamic behaviors in solid state materials., (© 2011 American Chemical Society)

This paper aims to illustrate the rich potential of the thioether-carboxyl combination in generating coordination networks with tunable and interesting structural features. By simply varying the ratio between Cu(NO(3))(2) and the bifunctional ligand tetrakis(methylthio)benzenedicarboxylic acid (TMBD) as the reactants, three coordination networks can be hydrothermally synthesized in substantial yields, which present a distinct evolution with regard to metal-ligand interactions. Specifically, Cu(TMBD)(0.5)(H(2)TMBD)(0.5)·H(2)TMBD (1) was obtained with a relatively small (1:1) Cu(NO(3))(2)/TMBD ratio, and crystallizes as an one-dimensional (1D) coordination assembly based on Cu(I)-thioether interactions, which is integrated by hydrogen-bonding to additional H(2)TMBD molecules to form a three-dimensional (3D) composite network with all the carboxylic acid and carboxylate groups remaining uncoordinated to the metal ions. A medium (1.25:1) Cu(NO(3))(2)/TMBD ratio leads to compound Cu(2)TMBD, in which Cu(I) ions simultaneously bond to the carboxylate and thioether groups, while an even higher (2.4:1) Cu(NO(3))(2)/TMBD ratio produced a mixed-cation compound Cu(II)(2)OHCu(I)(TMBD)(2)·2H(2)O (2), in which the carboxylic groups are bonded to (cupric) Cu(II) ions, and the thioether groups to Cu(I). Despite the lack of open channels in 2, crystallites of this compound exhibit a distinct and selective absorption of NH(3), with a concomitant color change from green to blue, indicating substantial network flexibility and dynamics with regards to gas transport.

A silver(I) sulfide species is now imbedded in a porous coordination network. Such a composite system builds on the molecule tetrakis(methylthio)-1,4-benzenedicarboxate that holds out the hard carboxylate to europium(III) to form a host net, while taking on AgCl using its soft sulfur side arms. AgCl is then treated with H(2)S to form the dark-colored Ag(2)S species, while leaving the hard host net intact and upstanding. This hard-soft duality serves to conjoin the rich electronic flavors of metal chalcogenides and the flexible textures of coordination nets.

The bifunctional molecule tetrakis(methylthio)-1,4-benzenedicarboxylic acid (TMBD) interacts with the increasingly harder metal ions of Cu (I), Cd (II), and Zn (II) to form the coordination networks of Cu 2TMBD, CdTMBD, and Zn 4O(H 2O) 3(TMBD) 3, where the carboxyl group consistently bonds to metal ions, while the softer methylthio group binds with preference to the softer metal ions (i.e., chelation to Cu (+), single-fold coordination to Cd (2+), and nonbonding to Zn (2+)). Diffuse-reflectance spectra show that the metal-thioether interaction is associated with smaller electronic band gaps of the solid-state networks.

Solvothermal reactions of CuSCN, metal (Mn2+, Fe2+, Co2+, Ni2+, Cu2+) sulfate, and terpyridine (2,2':6',2' '-terpyridine or 4'-p-tolyl-2,2':6',2' '-terpyridine) in the presence of triphenylphosphine yielded a series of hybrid coordination compounds, in which in situ formed metal bis(terpyridine) complex cations are encapsulated by a 3D anionic network or entangled by 2D heartlike networks, forming encapsulation or polypseudorotaxane supramolecules. The complex cations play a role as template to direct the fabrication of the structures.

Two unprecedented 3D polyknotted isomers, arisen from different linkage modes of SCN-, were obtained from 3,5-bis(4-pyridyl)-1H-pyrazole (Hbppz) and CuSCN under different conditions.

The reactions of 2,4,6-tri(2-pyridyl)-1,3,5-triazine (tpt) with copper(I) halides under solvothermal or traditional conditions yielded two polymeric Cu(I) complexes [Cu2I2(tpt)]n (1) and [Cu3I3(tpt)]n (2), one mixed-valence Cu(I)-Cu(II) complex [Cu4Cl2I4(tpt)2] (3), and two Cu(II) complexes [CuBr(bpca)] (4) and [CuI(bpca)] (5) (bpca = bis(2-pyridylcarbonyl)amine). Complex 1 is a zigzag chain with tpt in a bis-bipyridine-like coordination mode, whereas complex 2 with tpt chelating three Cu(I) cations is a ladderlike coordination polymer. Complex 3 is mixed-valence, with Cu(I) in a distorted tetrahedral geometry and Cu(II) in a distorted square pyramidal geometry, forming a ladderlike supramolecular chain. Complexes 4 and 5 are the products of in situ hydrolysis of tpt involving the oxidation of Cu(I). The synthesis and characterization of complex 1, 2, and 5 indicated that Cu(I) cannot promote the hydrolysis of tpt. The theoretical study shows that the main effect for hydrolysis of tpt is the electron-withdrawing effect of metal ions.

This work focuses on the systematic investigation of the influences of pyrimidine-based thioether ligand geometries and counteranions on the overall molecular architectures. A N-containing heterocyclic dithioether ligand 2,6-bis(2-pyrimidinesulfanylmethyl)pyridine (L1) and three structurally related isomeric bis(2-pyrimidinesulfanylmethyl)benzene (L2-L4) ligands have been prepared. On the basis of the self-assembly of CuX (X = I, Br, Cl, SCN, or CN) and the four structurally related flexible dithioether ligands, we have synthesized and characterized 10 new metal-organic entities, Cu4(L1)2I4 1, Cu4(L1)2Br4 2, [Cu2(L2)2I2.CH3CN]n 3, [Cu(L3)I]n 4, [Cu(L3)Br]n 5, [Cu(L3)CN]n 6, [Cu(L4)CN]n 7, [Cu2(L4)I2]n 8, [Cu2(L4)(SCN)2]n 9, and [[Cu6I5(L4)3](BF4).H2O]n 10, by elemental analyses, IR spectroscopy, and X-ray crystallography. Single-crystal X-ray analyses show that the 10 Cu(I) complexes possess an increasing dimensionality from 0D (1 and 2) to 1D (3-5) to 2D (6-9) to 3D (10), which indicates that the ligand geometry takes an essential role in the framework formation of the Cu(I) complexes. The influence of counteranions and pi-pi weak interactions on the formation and dimensionality of these coordination polymers has also been explored. In addition, the photoluminescence properties of Cu(I) coordination polymers 4-10 in the solid state have been studied.