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An expanded pyridyl-decorated MOF-505 analogue[Cu2(L)(H2O)2]·G(x) (H4L = 5,5'-(pyridine-2,5-diyl)diisophthalic acid, G = solvent molecule) has been solvothermally synthesized and reported. It exhibited rare hierarchical meso- and microporosity. With exposed unsaturated Cu(II) sites and Lewis basic pyridyl sites, the material shows both large CO2-uptake capacity (123.4 cm(3) g(-1) at 273 K, 1 bar) and high selectivity for CO2 over N2 (55.7) at 273 K. Furthermore, for the first time the compound has been exploited for its heterogeneous catalytic performance toward the cyanosilylation reaction under solvent-free conditions. The compound can be recycled up to five times with only a minor loss of activity.

A perfectly aligned 63 helical tubular cuprous bromide single crystal has been synthesized and characterized, which can selectively decompose negatively charged dyes of Methyl Orange (MO) and Kermes Red (KR), and the photocatalytic efficiency is higher than that of nanosized (∼25 nm) TiO2 and ZnO. The direction and magnitude of the dipole moments as well as the band structure were calculated to reveal high photocatalytic efficiency. Moreover, luminescence studies indicate that the CuBr tube materials show very strong yellowish green emissions in the solid state and emulsion even at room temperature, and exhibit extremely high detection sensitivity towards nitro-explosives via fluorescence quenching. Detectable luminescence responses were observed at a very low concentration of 20 ppm with a high quenching efficiency of 94.90%. The results suggest that they may be promising multifunctional materials for photo-catalysis, luminescence and sensing of nitro-explosives.

A perfectly square-planar, D(4h)-symmetric, tetracoordinated oxygen has been observed in a tetracopper cluster-based coordination polymer that shows an unusual magnetic moment and ESR signal. The stabilization factor of the square-planar tetracoordinated oxygen has been revealed using DFT calculations., (© 2011 American Chemical Society)

The non-classical KP(6)Mo(18)O(73) heteropolyanion has been studied by the density functional theory (DFT) method, and the calculated geometry compares well with the experimental one. In fully oxidized [KP(6)Mo(18)O(73)](7-) state, the d(xy)-orbitals centered at eight "belt" Mo sites in the lower part of the "basket" are the major contributors to the LUMO and LUMO+1, while the LUMO+2 orbital is mostly focused on the two polar parts. In contrast, the HOMOs indicates that the coordination of the KP(6)Mo(18) heteropolyanion to metal ions favorably occurs at the oxygen atoms from four external phosphates and two molybdates of the handle of the "basket". Compared with Wells-Dawson [P(2)Mo(18)O(62)](6-), the HOMO-LUMO gap in fully oxidized [KP(6)Mo(18)O(73)](7-) is much smaller, indicating much easier reduction that is consistent with the cyclic voltammogram. Both frontier orbitals and Mulliken analysis indicate that two of three blue electrons in [KP(6)Mo(18)O(73)](10-) (KP(6)Mo(18)-3e) have spin alpha while third blue electron has spin beta, in agreement with magnetic data. The four-copper complex of the non-classical KP(6)Mo(18)-3e heteropolyanion has been synthesized and structurally characterized; its structure supports the theoretical results such as reactivity and basicity of external oxygen sites.

Atomically precise copper nanoclusters with crystallization‐induced emission enhancement (CIEE) have garnered significant academic interests‐ but the rational design of high‐nuclearity Cu nanoaggregates with precise atomic structures and the CIEE effect remains a long‐standing challenge. Herein, a new atomically precise copper nanocluster co‐protected by thiolate, phosphine, and S2− ligands, formulated as Cu34S6(PFBT)22(PPh3)6 (Cu34, PFBT = pentafluorobenzenethiol, PPh3 = triphenylphosphine), is reported, which possesses a typical Cu12S6 core and a Cu22S22P6 shell. Under photoexcitation at 505 nm, Cu34 exhibits strong red‐light emission with a photoluminescence quantum yield of 4.1%. DFT calculations confirm that the emission stems from the ligand‐to‐metal charge transfer (LMCT) transition. This nanoaggregate shows a strong CIEE effect, with the crystalline form exhibiting an 800‐fold enhancement in emission intensity compared to its solution form. An in‐depth structural investigation of the ligand shell reveals that the extensive C−H···F, C−H···π, and π···π interactions significantly restrict the intra‐ and inter‐molecular rotations and vibrations, accounting for the CIEE phenomena. The red emission of Cu34 can be selectively quenched by CH3CN, with a lower detection limit of 9.36 µM (0.38 ppm). This study advances the development of high‐nuclearity copper nanocluster with the CIEE effect and holds significant potential for applications in selectively sensing volatile organic compounds (VOCs). [ABSTRACT FROM AUTHOR]

Ligand‐protected heterometallic nanoclusters in contrast to homo‐metal counterparts show more broad applications due to the synergistic effect of hetero‐metals but their controllable syntheses remain a challenge. Among heterometallic nanoclusters, monovalent Ag‐Cu compounds are rarely explored due to much difference of Ag(I) and Cu(I) such as atom radius, coordination habits, and redox potential. Encouraged by copper‐catalyzed alkyne‐azide cycloaddition (CuAAC) reaction, comproportionation reaction of Cu(II)X2 and Cu(0) in the presence of (PhC≡CAg)n complex and molybdate generated a core‐shell peanut‐shaped 66‐nuclear Ag(I)‐Cu(I) heterometallic nanocluster, [(Mo4O16)2@Cu12Ag54(PhC≡C)50] (referred to as Ag54Cu12). The structure and composition of Ag‐Cu heterometallic nanocluster are fully characterized. X‐ray single crystal diffraction reveals that Ag54Cu12 has a peanut‐shaped silver(I)/copper(I) heterometallic nanocage protected by fifty phenylacetylene ligands in µ3–modes and encapsulated two mutually twisted tetramolybdates. Heterometallic nanocage contains a 54‐Ag‐atom outer ellipsoid silver cage decorated by 12 copper inside wall. Nanosized Ag54Cu12 is a n‐type narrow‐band‐gap semiconductor with a good photocurrent response. Preliminary experiments demonstrates that Ag54Cu12 itself and activated carbon supported Ag54Cu12/C are effective catalysts for 1,3‐dipole cycloaddition between alkynes and azides at ambient conditions. The work provides not only a new synthetic route toward Ag(I)‐Cu(I) nanoclusters but also an important heterometallic intermediate in CuAAC catalytic reaction. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: To search for novel Cu(I) complexes, traditional approaches focus on designing and screening ligands, metal precursors and reaction parameters. In this report, we propose a top‐down approach, in which Cu precursor is first reduced to nanoparticles in the presence of alkynyl and phosphine ligands. The nanoparticles then undergo an auto‐oxidation step in open air to give CuO powder. During this process, a new tetranuclear Cu(I) cluster with an unprecedented centered triangular configuration, [Cu4(PhC≡C)3(dppp)3]NO3, is isolated in the supernatant. To demonstrate the feasibility of such strategy, it is applied to synthesize another two new Cu(I) clusters, [Cu6 (PhC≡C)5(dppe)3]NO3 and Cu4(PhC≡C)4(dpph)2. The latter has shown a photoluminescence at 511 nm with a quantum yield of as high as 69.84%. [ABSTRACT FROM AUTHOR]

The only feasible access to non‐face‐centered cubic (FCC) copper was by physical vapor deposition under high vacuum. Now, non‐FCC copper is observed in a series of alkynyl‐protected Cu53 nanoclusters (NCs) obtained from solution‐phase synthesis. Determined by single‐crystal X‐ray crystallography, the structures of Cu53(C≡CPhPh)9(dppp)6Cl3(NO3)9 and its two derivatives reveal an ABABC stacking sequence involving 41 Cu atoms. It can be regarded as a mixed FCC and HCP structure, which gives strong evidence that Cu can be arranged in non‐FCC lattice at ambient conditions when proper ligands are provided. Characterization methods including X‐ray absorption fine structure, XPS, ESI‐MS, UV/Vis, Auger spectroscopy, and DFT calculations were carried out. CuII was shown to successively coordinate with introduced ligands and changed to CuI after bonding with phosphine. The following addition of NaBH4 and the aging step further reduced it to the Cu53 NC. [ABSTRACT FROM AUTHOR]

By using environmentally friendly [Ni(CN)4]2− as a cyanide source, three new heterometallic cyano-bridged mixed-valence CuI/CuII with three different electronic configurations (d8-d10), that is, [Cu2Ni(CN)5(H2O)3] ( 1), [Cu2Ni(CN)5(pn)H2O] ( 2), and [Cu3Ni(CN)6(pn)2] ( 3, pn=1,2-propane diamine) have been synthesized by gradually increasing the amount of pn. Compound 1, which was hydrothermally synthesized in the absence of pn ligand, exhibits the famous 2D Cairo pentagonal tiling, in which the CuI, CuII, and NiII atoms act as trigonal, T-shaped, and square-planar nodes, respectively. Notably, there are three water molecules located at the meridianal positions of the octahedrally coordinated CuII atom in compound 1. A similar reaction, except for the addition of a small amount of pn, generated a similar Cairo pentagonal tiling layer in which two of the water molecules that were located at the meridianal positions of the octahedrally coordinated CuII atom were replaced by a chelating pn group. Another similar hydrothermal reaction, with the addition of a larger amount of pn, yielded compound 3, which showed a related two-fold-interpenetrated (3,4)-connected 3D framework with an unprecedented {83}2{86} topology in which the CuII atom was chelated by two pn groups. These structural changes between compounds 1, 2, 3 can be explained by the chelating effect of the pn group. The replacement of two meridianally coordinated water molecules on the octahedral CuII atom in compound 1 by a pn group gives compound 2, which shows similar Cairo tiling, and a further increase in the amount of pn results in the formation of the [Cu(NC)2(pn)2] unit and the two-fold-interpenetrated 3D framework of compound 3. The mixed-valence properties of compounds 1, 2, and 3 were confirmed by variable-temperature magnetic-susceptibility measurements. [ABSTRACT FROM AUTHOR]

Five tetrazolate-based coordination polymers with cationic copper(I) halide motifs, namely, Cu4(tta)2Cl2 ( 1, tta = tetrazolate), Cu4(tta)2Br2 ( 2), Cu2(tta)I ( 3), Cu3(mtta)2Cl ( 4, mtta = 5-methyltetrazolate), and Cu2(tta)Br ( 5) were prepared by hydro(solvo)thermal reactions of CuX2 or CuX with tetrazolato ligands in the presence of HX. Compounds 1, 2, and 3 show eight-connected square-planar layered structures constructed with butterfly-like [Cu4X2]2+ (X = Cl, Br, I) clusters and μ4-tta groups. Isomorphs 1 and 2 crystallize in the orthorhombic space group Pbca, but 3 crystallizes in the orthorhombic space group Pbam, because each μ4-tta group is coordinated to three butterfly-like clusters rather than four in 1 and 2. To the best of our knowledge, 1, 2, and 3 represent the only 2D coordination polymers with eight-connected square planar topology to date. Compound 4 is a [Cu3Cl]2+ cluster based on the undocumented ten-connected ZrIn2 topological framework. Compound 5 has a 3D pillar layered framework constructed with [Cu2Br] nn+ cationic layers. Compounds 1, 2, 4, and 5 exhibit strong green-blue emission in the solid state at room temperature, whereas cuprous iodide complex 3 shows strong red luminescence. [ABSTRACT FROM AUTHOR]

Abstract: Hydrothermal reaction of copper(II) chloride with 2-hydroxypyrimidine generated double salt of [Cu2Cl(μ4-pymo)] (1) (Hpymo=hydroxylpyrimidine) while hydrothermal treatment of CuCl2, NaN3 and acetonitrile resulted in double salt of [Cu2(mtta)Cl] (2) (Hmtta=5-methyltetrazole) in which in situ [2+3] cycloaddition reactions of acetonitrile with azide formed mtta ligand. X-ray single crystal structural analyses revealed that 1 shows a two-dimensional layer formed by fusion of one-dimensional structural motifs. The two-dimensional layers in 1 are held together by C–H⋯Cl hydrogen bonds to form three-dimensional supramolecular array. Compound 2 has a three-dimensional framework constructed from ribbons and [Cu8Cl4]4+ units. Uncommon coordination modes of μ4-1,2κO:3κN:4κN′ pymo and μ4-Cl (Cl at the apex of a Cu4Cl square pyramid) in 1 and μ4-η1:η1:η1:η1 mtta in 2 were also observed. The short Cu(I)⋯Cu(I) distances were found in 1 and 2, indicating the existence of Cu(I)⋯Cu(I) interactions. [Copyright &y& Elsevier]

Abstract: Hydrothermal reaction of CuBr2, 4,4′-bipyridine and ethanol/methanol generated two copper (I) bromide complexes with in situ alkylated 4,4′-bipyridium, namely [C14H18N2][Cu5Br7] (1) and [C12H14N2][Cu4Br6] (2). The structure of 1 consists of chains and N,N′-diethyl-4,4′-bipyridinium. The underlying structural motif in of 1 is the Cu5Br capped square pyramid, which is different from the Cu5Br2 pentagonal bipyramidal structural motif in various documented anions. The in 1 contains untypical μ5-bromide, with which five copper atoms forms a capped square pyramid rather than a pentagonal pyramid as predicted by Subramanian and Hoffmann. Compound 2 is isostructural with [C12H14N2][Cu4Cl6] reported by Willett, and consists of chains and N,N′-dimethyl-4,4′-bipyridinium. The chain is composed of alternating Cu6Br6 and Cu2Br6 units. [Copyright &y& Elsevier]

Abstract: Hydrothermal reaction of molybdenum oxide and copper(II) source in the presence of 4,4′-bipyridine (4,4′-bpy) afforded three-dimensional covalent framework [CuII(4,4′-bpy)(MoO4)] (1), while reaction with 1,4-diazoniabicyclo[2,2,2]octane (DABCO) in place of 4,4′-bpy and addition of metal molybdenum resulted in one-dimensional chain-like compound . The copper in 1 is divalent and approximately shows trigonal bipyramidal geometry, while in 2 is monovalent and approximately shows T-shaped geometry. The structure of 1 has a three-dimensional pillar-layered framework constructed from bimetallic {CuMoO4} layers bridged by bifunctional ligand 4,4′-bpy. Interestingly, the {CuMoO4} layer in 1 consists of 16-membered {Cu4Mo4O8} rings and 8-membered {Cu2Mo2O4} rings, different from other reported {CuMoO4} layers. The structure of 2 consists a one-dimensional chain that is attached by peripheral {Cu(HDABCO)}2+ units. The chain is constructed from octamolybdates through common corners. [Copyright &y& Elsevier]

The selective catalytic oxidation of alcohols is important both in laboratory and industrial production, and traditional oxidants cause environmentally lethal wastes. The development of dioxygen selective oxidation efficient has been pursued from atom-efficient, economic and environmental view of points. Using DFT calculation and ESI-MS experiments, we studied the activation of the Cu Cu bonded planar complex Cu 2 (ophen) 2 to dioxygen and the application of the dioxygen-copper system for the selective oxidation of alcohols. For practical application and green chemistry, this catalytic system avoided the use of a large excess of base and expensive nitroxyl derivatives. In the cycle of oxidation, two oxidative dehydrogenation processes featuring superoxide/peroxide ( I ) and hydroperoxide ( II ) occurred along with a series of conformational changes of the butterfly-like Cu-complex from stretched to folded to stretched. Additionally, we characterized the role of the water molecule as a proton mediator in the dioxygen-copper system. [ABSTRACT FROM AUTHOR]

Colorless needle-like crystals of α-(NMe4)[Cu2I3] are prepared by solvothermal reaction of CuI, hexamethylenetetramine, and HI in MeOH in a molar ratio of 5:2:7:150 (autoclave, 150 °C, 120 h; 61% yield). [ABSTRACT FROM AUTHOR]