A host-guest complex between a metal-organic cyclotriveratrylene analog and a polyoxometalate: [Cu6(4,7-phenanthroline)8(MeCN)4]2PM12O40(M = Mo or W)

The synthesis and crystal structure of Cu(6)(4,7-phenanthroline)(8)(MeCN)(4)(6+) a novel Cu(i)-molecular hexamer is described in which the metal cations and phenanthroline molecules self-assemble into a dimer of shallow triangular-shaped bowls, within which are located large spherical polyoxometalate anions PM(12)O(40)(3-)(M = Mo or W).     

A polyoxometallate-templated coordination polymer: synthesis and crystal structure of [Cu3(4,4'-bipy)5(MeCN)2]PW12O(40).2C6H5CN

The spherical phosphotungstate ion, PW12O40(3-), has been used as a non-coordinating anionic template for the construction of a novel, three-dimensional Cu(I) coordination polymer.     

Onc 0 sequences in Banach spaces

A Banach space has property (S) if every normalized weakly null sequence contains a subsequences equivalent to the unit vector basis ofc ₀. We show that the equivalence constant can be chosen “uniformly”, i.e., independent of the choice of the normalized weakly null sequence. Furthermore we show that a Banach space with property (S) has property (u). This solves in the negative the conjecture that a separable Banach space with property (u) not containingl ₁ has a separable dual. This is part of this author's Ph.D. dissertation prepared at The University of Texas at Austin under the supervision of H. P. Rosenthal.     

Crystal and molecular structures of several tetrakis (nitrile)copper(I) complexes

The crystal structures of several [Cu(RCN)₄]X salts (R = Me, X = SO₃CF₃ ^–; R = Ph, X = BF₄ ^–, ClO₄ ^–, and PF₆ ^–) were determined using single crystal X-ray diffraction. All of the compounds contain distorted tetrahedral Cu(I) centers and noncoordinating anions, with the acetonitrile and benzonitrile structures containing three and one unique CuL₄ ⁺ complex in their respective asymmetric units. One important distortion is observed in the benzonitrile-Cu bonds, which are bent up to 23° away from linearity. The result is a flattened complex that maximizes the – tacking of the aromatic rings and is the dominant packing interactions between the complexes.     

A mixed-ligand coordination polymer from the in situ,Cu(I)-mediated isomerization of bis(4-pyridyl)ethylene

Reaction of [Cu(PPh(3))(2)(MeCN)(2)]PF(6) and trans-1,2-bis(4-pyridyl)ethylene (bpe) results in the trans-cis isomerization of the bpe and subsequent formation of a mixed-isomer linear coordination polymer over the course of several days or weeks depending on solvent. The one unique copper atom in the structure is coordinated to two bridging cis-bpe ligands, one bridging trans-bpe ligand, and one terminal triphenylphoshine ligand to create [Cu(trans-bpe)(0.5)(cis-bpe)(PPh(3))](+)( infinity ) zigzag chains. The reaction requires both visible light and Cu(I), and the crystallization of this particular coordination polymer is insensitive to the ratio of trans:cis isomers in solution, occurring both from trans-rich and cis-rich solutions.     

Phototransformation of monovinyl and divinyl protochlorophyllide by NADPH:Protochlorophyllide oxidoreductase of barley expressed in Escherichia coli

The chlorophyll precursors monovinyl protochlorophyllide (MV-PChlide) and divinyl protochlorophyllide (DV-PChlide) were extracted from mutant C-2A' of the unicellular green alga Scenedesmus obliquus which accumulates both protochlorophyllide derivatives in the dark. The two pigments were characterized by absorption and fluorescence spectroscopy and by plasma desorption mass spectrometry. The molecular masses of MV-PChlide and DV-PChlide were determined as 612 and 610 atomic mass units (amu) respectively. Both MV-PChlide and DV-PChlide were accepted as substrates and photoconverted to chlorophyllides in vitro by NADPH:protochlorophyllide oxidoreductase of barley expressed in Escherichia coli.     

On Asymptotic Structure,the Szlenk Index and UKK Properties in Banach Spaces

Let B be a separable Banach space and let X=B ^* be separable. We prove that if B has finite Szlenk index (for all > 0) then B can be renormed to have the weak* uniform Kadec-Klee property. Thus if > 0 there exists () > 0 so that if x _n is a sequence in the ball of X converging ^* to x so that . In addition we show that the norm can be chosen so that () c^p for some p < and c >0.     

Synthesis and structures of Na4P2Se6, Cs3PSe4, and Rb4P2Se9

Na₄P₂Se₆ (1) crystallizes in the orthorhombic space group Cmca (No. 64) with a = 11.836(3) ?, b = 13.311(4) ?, c = 8.061(2) ?, V = 1270.0(6) ?³, Z = 4, and, D _c = 3.283 g/cm³. Na₄P₂Se₆ belongs to the family of compounds with the general formula where A = Na⁺ and Q = Se²⁻. The crystal structure consists of isolated ethane-like P₂Se anions surrounded by Na⁺ cations. Cs₃PSe₄ (2) crystallizes in the orthorhombic space group Pnma (No. 62) with a = 10.0146(9) ?, b = 11.9899(10) ?, c = 9.9286(9) ?, V = 1192.17(18) ?3, Z = 4, and, Dc = 4.154 g/cm³. Cs₃PSe₄ belongs to the family of compounds with the general formula [(A^{+ x} ) _{z / x} (P ^v Q₄)^{− z} ] where A = Cs⁺ and Q = Se²⁻. The crystal structure consists of isolated methane-like PSe anions surrounded by Cs⁺ cations. Rb₄P₂Se₉ (3) crystallizes in the monoclinic space group C2/c (No. 15), a = 9.725(2) ?, b = 10.468(3) ?, c = 19.155(5) ?, β = 93.627(5)°, V = 1946.1(8) ?³, Z = 4, D _c = 3.804 g/cm³. Rb₄P₂Se₉ belongs to the family of compounds with the general formula [(A^{+ x} )_{(2 z −2)/ x} (Q₃PQ′—Q″—Q′PQ₃)^{−(2 z −2)}] where A = Cs⁺ and Q = Se²⁻, Q′ = Se¹⁻, Q″ = Se⁰. The crystal structure consists of isolated P₂Se anions surrounded by Rb⁺ cations.