Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTHigh-Spin Molecules: Hexanuclear [Mn6O4Cl4(Me2dbm)6] (Me2dbmH = 4,4'-Dimethyldibenzoylmethane) with a Near Tetrahedral [Mn6O4Cl4]6+ Core and a S = 12 Ground StateGuillem Aromí, Juan-Pablo Claude, Michael J. Knapp, John C. Huffman, David N. Hendrickson, and George Chris…
Two new iron(III) complexes of the formulas [Fe(bpm)Cl 3 (H 2 O)]·H 2 O ( 1 ) and [Fe 2 (bpm)Cl 6 (H 2 O) 2 ]·2H 2 O ( 2 ) (bpm = 2,2‘-bipyrimidine) have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. 1 and 2 crystallize in the monoclinic system, space group P 2 1 / n, wi…
Lipophilic lanthanide complexes of fluorinated β-diketonate ligands were demonstrated to bind unprotected phenylalanine, leucine, and other amino acids under neutral conditions. Extraction experiments supported that these lanthanide tris(β-diketonates) formed highly coordinated 1:1 complexes with amino acids, although…
The new macrocycle tetrakis(thiadiazole)porphyrazine, TTDPzH 2, has been prepared, in CF 3 COOH, from its corresponding Mg(II) derivative, [TTDPzMg(H 2 O)]·CH 3 COOH, which, in turn, is obtained by the reaction of magnesium(II) propylate and 3,4-dicyano-1,2,5-thiadiazole. The Mg(II) complex is also used for the prepar…
Various types of poly(aspartic acid)s, which were poly(α- l -aspartic acid), poly(α- d -aspartic acid), poly(β- l -aspartic acid), and poly(α,β- d, l -aspartic acid)s, were prepared, and their biodegradabilities using the OECD 301C method and calcium ion chelating abilities were measured to clarify the relationship be…
In a melt-miscible crystalline/amorphous polymer blend, crystallization is accompanied with the segregation of amorphous diluent. Depending on the distance of segregation, various types of segregation morphology, including interlamellar, interfibrillar, and interspherulitic, may be created. In this study, we systemati…
Synthetic green rusts, GRs, are prepared by oxidation of Fe(OH) 2 incorporating Cl -, SO 4 2-, or CO 3 2- ions. E h −pH diagrams are drawn, and thermodynamic data are derived. A GR incorporating OH - ions, GR1(OH - ), is suspected to exist like similar other M(II)−M(III) compounds. GRs form as corrosion products of st…
The chemical or electrochemical oxidations and coupled chemical reactions of (TPP)Co(R) and (TPP)Co(R)(L) where R = Bu, Et, Me, or Ph, L = a substituted pyridine, and TPP = the dianion of tetraphenylporphyrin were investigated in acetonitrile or dichloromethane. The homogeneous one- or two-electron oxidation of the Co…
The electronic quasiparticle structure of a ferromagnetic local moment film is investigated within the framework of the s-f model. For the special case of a single electron in an otherwise empty energy band being exchange coupled to a fully ordered localised spin system the problem can be solved exactly and, for the s…
The first examples of carbachlorins (1) have been synthesized by the “3 + 1” methodology. Unlike true chlorins, these structures resist further oxidation to porphyrin. However, these novel aromatic structures resemble the tetrapyrrolic species in that they retain strong red-shifted absorptions in their electronic spec…
The orthogonality strategy provides a logical design principle for aromatic columns and microporosity in molecular crystals. An orthogonal porphyrin–bisresorcinol derivative 1 forms an extensive hydrogen-bonded network in which the porphyrin rings are forced into columns; the large cavities left can incorporate guest…
A substantial enhancement in the nonlinear optical properties of three-dimensional NLO chromophores in which three or four 4′-dibutylaminoazobenzenyl moieties are connected through a central phosphonium ion (right) is observed relative to the corresponding one-dimensional compound. This contrasts with the linear optic…
A series of heterobimetallic complexes [(V IV O)L1Cu II (μ-OAC)(MeOH)](ClO 4 ) ( 1 ) and [(V IV O)L1M II (μ-OAc)(H 2 O)](ClO 4 )·H 2 O (M = Ni ( 2 ), Co ( 3 ), Fe ( 4 ), Mn ( 5 )) derived from a symmetric tetraaminodiphenol macrocyclic ligand H 2 L1 have been synthesized and characterized. The crystal structure of 1 h…
We have studied the microdomain pattern in a block copolymer system using a recently developed imaging technique. We observe pronounced registry of microdomains from layer to layer, the propagation and evolution of disclinations, and novel morphologies which form at the edge of an island. The imaging of the microdomai…
A recently developed computational strategy is applied to examine the influence of several factors on the exchange coupling constants of oxalato-bridged copper(II) binuclear complexes (shown schematically here); molecular topology, the nature of terminal ligands and selected structural parameters are discussed.
Control over calcium carbonate deposition in an in vitro system containing the major macromolecular components present in mollusk shell is shown to depend on the presence of a specific protein fraction in the appropriate microenvironment, in this case, silk fibroin adsorbed on β-chitin. Experiments with synthetic poly…
We present recent results on two attempts at understanding and utilizing large-scale simulations of magnetic materials. In the first study we consider massively parallel implementations on a Cray T3E of the n-fold way algorithm for magnetization switching in kinetic Ising models. We find an intricate relationship betw…
In this paper, the hyperfine quadrupole interaction at the Zr-Ti site of (PZT) polycrystalline samples is studied for the first time. Powders for x = 0, 0.1, 0.2, 0.4, 0.6, 0.8, 0.9 and 1 were prepared and characterized by XRD. The lattice constants and space groups were obtained as functions of Ti concentration. PAC…
The temperature dependence of the acoustic dispersion relation, $\ensuremath{\Omega}(Q,T)$, has been determined across the liquid-glass transition in o-terphenyl using inelastic x-ray scattering in the $1--6{\mathrm{nm}}^{\ensuremath{-}1}$ momentum transfer ( $Q$) range. From this the infinite frequency sound velocity…
Resistance measurements in the ``normal'' state of $(\mathrm{TMTSF}{)}_{2}{\mathrm{PF}}_{6}$ under pressure for different magnetic field orientations show striking features below 5 K. We observe metallic behavior $(\frac{\mathrm{dR}}{\mathrm{dT}}>0)$ when the field is aligned along the intermolecular tunneling dire…