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41.
The synthesis of a series of lanthanide tetracyanoplatinates all incorporating 2,2′:6′,2″-terpyridine (terpy) have been carried out by reaction of Ln3+ nitrate salts with terpy and potassium tetracyanoplatinate. The incorporation of different Ln3+ cations results in the isolation of [Ln(DMF)2(C15H11N3)(H2O)2(NO3)]Pt(CN)4 (Ln=La-Nd, Sm-Yb) under otherwise identical reaction conditions. These compounds have been isolated as single crystals and X-ray diffraction has been used to investigate their structural features. All of the reported compounds are isostructural. Crystallographic data for the representative Eu3+ compound (EuPt) are (MoKα, λ=0.71073 Å): monoclinic, space group P21/c, a=10.1234(4) Å, b=18.7060(7) Å, c=17.1642(5) Å, β=97.249(3)°, V=3224.4(2), Z=4, R(F)=2.78% for 426 parameters with 7724 reflections with I>2σ(I). The structure consists of a zero-dimensional, ionic salt containing complex [Eu(DMF)2(C15H11N3)(H2O)2(NO3)]2+ cations and anions. The complex cations contain the Eu3+ ions in a tri-capped trigonal prismatic coordination environment with one terdentate 2,2′:6′,2″-terpyridine molecule, one bidentate nitrate anion, two O-bound dimethylformamide molecules, and two coordinated water molecules. Photoluminescence data illustrate that EuPt displays intramolecular energy transfer from the coordinated terpy molecule to the Eu3+ cation. The uncoordinated tetracyanoplatinate anion also exhibits visible emission. 相似文献
42.
Sykora M Petruska MA Alstrum-Acevedo J Bezel I Meyer TJ Klimov VI 《Journal of the American Chemical Society》2006,128(31):9984-9985
In this communication, we demonstrate a new approach to sensitization of Ru-polypyridine complexes by using semiconductor nanocrystal quantum dots (NQDs). When mixed in solution, the complexes functionalized by carboxylic groups adsorb onto the surface of the NQDs. Excitation of NQDs by 400 nm light leads to fast, 5 ps hole transfer from the photoexcited NQDs to the surface-adsorbed complexes. This result indicates that Ru complexes can be sensitized by CdSe NQDs, which opens interesting opportunities for designing new types of photocatalytic materials for solar energy conversion applications. These materials will take advantage of broad size-controlled absorption spectra and large extinction coefficients of NQDs as well as the unique property of NQDs to respond to absorption of a single photon by producing multiple electron-hole pairs. 相似文献
43.
44.
Pavel Lhoták Roman ZiebaVit Hromádko Ivan Stibor Jan Sykora 《Tetrahedron letters》2003,44(24):4519-4522
The introduction of two aromatic aldehyde moieties into the lower rim of calix[4]arenes led to the precursors that were intramolecularly bridged in the presence of low-valent titanium agents (the McMurry reaction). These compounds, preorganised in the cone conformation, represent novel receptors with good complexation ability towards suitable neutral guest molecules both in solution and in the solid state. The influence of preorganisation and overall rigidity of receptor to the complexation process has been studied. 相似文献
45.
46.
Monolayers of the antifungal antibiotic amphotericin B undergo the liquid expanded/liquid condensed state transition if spread from chloroform/methanol solvent. The transition disappeared after a long spreading time. The presence of the transition may be due to the retention of solvent and/or the presence of metastable aggregates of amphotericin B. 相似文献
47.
Surface-pressure (Pi) and surface-area isotherms as a function of surface area were measured for monolayers of amphotericin B (AmB) and cholesterol mixtures at the air/water interface at 10, 20, and 30 degrees C. When chloroform/methanol was used as a spreading solvent, the Pi-A isotherms of the mixed monolayers exhibited characteristic transitions from the gas to liquid-expanded, then liquid-condensed, and finally the solid state. The expanding effect in monolayers was accompanied by a large Pi-A hysteresis and a positive excess of free energy of mixing at high Pi. At low Pi, a condensing effect was observed with the most significant deviation from ideality occurring at a mole fraction of AmB (XAmB) of 0.67. Free energy calculations revealed a condensing effect at low Pi and an expanding effect at high Pi except at 30 degrees C, where a condensing effect was observed for XAmB around 0.33. In contrast, when 2-propanol/water was used as spreading solvent, the mixed monolayers at 20 degrees C exhibited Pi-A isotherms which obey van der Waals equation of state, with no visible transitions, low hysteresis, a condensing effect, and a negative free energy of mixing. The most stable monolayers were produced from mixtures of AmB and cholesterol with a 2:1 stoichiometry. 相似文献
48.
Robin T. Macaluso Richard E. Sykora Arthur Mar H. Lee Julia Y. Chan 《Journal of solid state chemistry》2004,177(1):293-298
The ternary antimonide CeNiSb3 has been prepared from an Sb flux or from reaction of Ce, NiSb, and Sb above 1123 K. It crystallizes in the orthorhombic space group Pbcm with Z=12 and lattice parameters a=12.6340(7) Å, b=6.2037(3) Å, and c=18.3698(9) Å at 193 K. Its structure consists of buckled square nets of Sb atoms and layers of highly distorted edge- and face-sharing NiSb6 octahedra. Located between the ∞2[Sb] and ∞2[NiSb2] layers are the Ce atoms, in monocapped square antiprismatic coordination. There is an extensive network of Sb-Sb bonding with distances varying between 3.0 and 3.4 Å. The structure is related to that of RECrSb3 but with a different stacking of the metal-centered octahedra. Resistivity measurements reveal a shallow minimum near 25 K that is suggestive of Kondo lattice behavior, followed by a sharp decrease below 6 K. 相似文献
49.
W.?BehrEmail author A.?Sykora 《The European Physical Journal C - Particles and Fields》2004,35(1):145-148
Open Wilson lines are known to be the observables of non-commutative gauge theory with Moyal-Weyl *-product. We generalize these objects to more general *-products. As an application we derive a formula for the inverse Seiberg-Witten map for *-products with invertible Poisson structures.Received: 13 February 2004, Revised: 1 March 2004, Published online: 8 April 2004 相似文献
50.
The acid-functionalized tris-heteroleptic chromophore--donor--acceptor assembly [RuII(bpyCOOH)(bpyCH2PTZ)(bpyCH2MV2+)](PF6)4]4+ (1) (bpyCOOH = 4'-methyl-2,2'-bipyridine-4-carboxylic acid; bpyCH2PTZ = 10-((4'-methyl-2,2'-bipyridin-4-yl)methyl)phenothiazine; bpyCH2MV2+ = 1-((4'-methyl-2,2'-bipyridin-4-yl)methyl)-1'-methyl- 4,4'-bipyridinediium) was synthesized in a one-pot reaction by careful selection of the order of ligand addition to RuCl2(DMSO)4 (DMSO = dimethyl sulfoxide). The success of this method was based upon separation and isolation of 1 from mixtures containing ligand-scrambled products by cation exchange chromatography. Metal-to-ligand charge-transfer (MLCT) excitation in acetonitrile at 464 nm was followed by intramolecular electron transfer to give a redox-separated state [RuII(bpyCOOH)(bpyCH2PTZ.+)(bpyCH2MV.+)]4+ with an efficiency of eta RS = 0.35 +/- 0.05. 相似文献