131 research outputs found

    Gas Sorption and Luminescence Properties of a Terbium(III)-Phosphine Oxide Coordination Material with Two-Dimensional Pore Topology

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    The structure, stability, gas sorption properties and luminescence behaviour of a new lanthanide-phosphine oxide coordination material are reported. The polymer PCM-15 is based on Tb(III) and tris(p-carboxylated) triphenylphosphine oxide and has a 5,5-connected net topology. It exhibits an infinite three-dimensional structure that incorporates an open, two-dimensional pore structure. The material is thermally robust and remains crystalline under high vacuum at 150 degrees C. When desolvated, the solid has a CO2 BET surface area of 1187 m(2) g(-1) and shows the highest reported uptake of both O-2 and H-2 at 77 K and 1 bar for a lanthanide-based coordination polymer. Isolated Tb(III) centres in the as-synthesized polymer exhibit moderate photoluminescence. However, upon removal of coordinated OH2 ligands, the luminescence intensity was found to approximately double; this process was reversible. Thus, the Tb(III) centre was used as a probe to detect directly the desolvation and resolvation of the polymer.Welch Foundation F-1738, F-1631National Science Foundation 0741973, CHE-0847763Chemistr

    4-[Tris(1H-pyrazol-1-yl)meth­yl]phenol

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    The title compound, C16H14N6O, was prepared by the condensation of 4-(trifluoro­meth­yl)phenol and sodium pyrazol-1-ide in a yield of 58%. The dihedral angles formed by the planes of the pyrazole rings are 50.7 (2), 71.2 (3) and 95.8 (2)°. The mol­ecules are associated into dimers by pairs of inter­molecular O—H⋯N hydrogen bonds involving the hy­droxy groups and pyrazole N atoms. In addition, π–π stacking between the phenol rings of these inversion-related dimers is observed, with a ring centroid-to-centroid distance of 3.9247 (10) Å

    Potassium bis­(1,1,1,5,5,5-hexa­fluoro­pentane-2,4-dionato)bis­(4,4,4-trifluoro-1-phenyl­butane-1,3-dionato)europate(III)

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    In the crystal structure of the title complex, K[Eu(C5HF6O2)2(C10H6F3O2)2], the EuIII ion is in a slightly distorted square-anti­prismatic coordination geometry which is defined by eight O atoms of the anionic β-diketone ligands. The two K+ ions lie on crystallographic inversion centers. The Eu—O bond distances are in the range 2.294 (5)–2.413 (5) Å. The crystal used was a non-merohedral twin, the ratio of the twin domains being 0.5236 (5):0.4764 (5)

    1,1′,1′′-{[4-(3,4-Ethyl­ene­dioxy­thio­phen-2-yl)phen­yl]methane­tri­yl}tris­(1H-pyra­zole)

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    In the title complex, C22H18N6O2S, two of the pyrazole rings are disordered over two sets of sites with ratios of refined occupancies of 0.58 (2):0.42 (2) and 0.517 (12):0.483 (12). The dioxane ring is in a half-chair conformation and the two –CH2– groups of this ring are disordered over two sets of sites, the ratio of refined occupancies being 0.855 (19):0.145 (19). The essentially planar thio­phene ring [largest deviation = 0.0444 (2) Å] forms a dihedral angle of 19.59 (3)° with the benzene ring

    {μ-6,6′-Dimeth­oxy-2,2′-[butane-1,4-diylbis(nitrilo­methyl­idyne)]diphenolato-1:2κ8 O 6,O 1,O 1′,O 6′:O 1,N,N′,O 1′}tris­(nitrato-1κ2 O,O′)copper(II)gadolinium(III)

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    In the title dinuclear complex, [CuGd(C20H22N2O4)(NO3)3], the CuII ion is located in the inner N2O2 cavity of the Schiff base ligand and adopts a distorted square-planar geometry. The GdIII ion is ten-coordinate being bound to ten O atoms, four from the Schiff base ligand and six from three bidentate nitrate anions. The CuII and GdIII ions are linked by two phenolate O atoms of the Schiff base ligand, with a separation of 3.5185 (9) Å

    Anion-Dependent Construction of Two Hexanuclear 3D-4F Complexes with a Flexible Schiff Base Ligand

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    Two hexanuclear 3d-4f Ni-Eu and Cu-Eu complexes [Eu4Ni2L2(OAc)(12)(EtOH)(2)] (1) and [Eu4Cu2L2(OAc)(12)]center dot 2H(2)O (2) are reported which are formed from the salen type Schiff-base ligand H2L (H2L = N,N'-bis(3-methoxysalicylidene)butane-1,4-diamine). In both complexes, four Eu3+ cations are bridged by eight OAc- groups and the chain is terminated at each end by two ML (M = Ni and Cu) units. The structures of 1 and 2 were determined by single crystal X-ray crystallographic studies and the luminescence properties of the free ligand and metal complexes in solution were measured.HHMI Undergraduate Science Education Award 52005907National Science Foundation CHE-0629136, CHE-0741973, CHE-0847763Welch Foundation F-1631, F-816Hong Kong Baptist University FRG/06-07/II-16Hong Kong Research Grants Council HKBU 202407Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)Open Foundation of Jiangsu Province Key Laboratory of Fine Petrochemical Technology KF1005UT-CNM and UT-AustinChemistr

    A Sensor for Trace H2O Detection in D2O

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    PCM-22, a metal-organic framework material comprising triphenylphosphine and Ln3+ ions (Ln = Pr–Yb), exhibits solid-state luminescence at room temperature. Mixed-metal versions of PCM-22 that contain controlled amounts of Eu3+, Gd3+, and Tb3+ function as highly sensitive, broad-scope solid-state sensors that can rapidly identify unknown solvents by providing a unique “eight-factor” fingerprint. The sensors allow for immediate solvent identification via color changes that are obvious to the naked eye and also permit quantitative chemical analysis by uncomplicated spectrophotometry. These same materials achieve quantitative detection of H2O in D2O from 10 to 120,000 ppm. The detection of trace H2O is also demonstrated in a range of common solvents, including those incompatible with conventional laboratory titration methods. A series of luminescent phosphine coordination materials show diverse sensing capabilities. These solid-state sensor materials can detect trace H2O impurities in D2O from 10 to 120,000 ppm and can rapidly identify unknown solvents

    6-Bromo- N

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