Materials Literature
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The crystal structure and a phase transition of gadolinium orthoborate, GdBO 3, were studied by electron diffraction and X-ray powder diffraction. GdBO 3 crystallizes in the vaterite structure (LT), in a rhombohedral space group R 32 with the lattice constants of a = 6.6357(2) Å and c = 26.706(1) Å. The structure of t…
We describe the synthesis and characterization of alkyl-capped nanocrystalline Si (R̂- n −Si) prepared by the reaction of SiCl 4 with Mg 2 Si in ethylene glycol dimethyl ether (glyme) and surface-terminated with various alkyl groups, R̂- n −Si (R = methyl, ethyl, n -butyl, and n -octyl). This reaction produces crystal…
Hydrous ruthenium oxide (RuO 2 · x H 2 O or RuO x H y ) is a mixed electron−proton conductor with a specific capacitance as high as 720 F/g/proton, making it a candidate material for energy storage. The correlation between the structure and properties of RuO 2 · x H 2 O materials is not well understood due to their am…
A simple method to control the dosing of small adsorbate molecules onto solid surfaces from liquid solution is applied to quantitative surface-enhanced Raman scattering measurements on dielectric-overcoated silver-island films. The deposition method, based on substrate withdrawal from solution, is evaluated by measuri…
Nematic and left-handed chiral−nematic liquid crystals comprising methoxybiphenylbenzoate and ( S )−(−)-1-phenylethylamine pendants to a cyclohexane core were synthesized and characterized. Although pristine samples were found to be polycrystalline, thermal quenching following heating to and annealing at elevated temp…
Two layered tin(II) oxalate structures have been prepared by hydrothermal methods in the presence of structure-directing organic amines. The crystal data for these structures are as follows: oxalate I, [(CH 3 ) 2 NH(CH 2 ) 2 NH(CH 3 ) 2 ] 2+ [Sn 2 (C 2 O 4 ) 3 ] 2 - ·H 2 O, monoclinic, space group C 2/ c (no. 15), a =…
The tridentate trianion of N,N-bis(2-hydroxy-di-3,5-tert-butylphenyl)amine, H(3)L(3), forms 1:1 and 2:1 complexes with di-, tri-, or tetravalent transition metal ions where it can exist in four oxidation levels (C(28)H(40)NO(2))(3)(-)(,2)(-)(,1)(-)(,0), which are herein designated as L(3), L(2), L(1), and L(0), respec…
Optical reflectivity spectra were measured on cleaved surfaces of La1-xSrxMnO3 single crystals (x=0.175, T_C=283 K) over a temperature range 10-295 K. The optical conductivity $sigma(ω)$ shows, keeping single-component nature, incoherent-to-coherent crossover with increase of electrical conductivity. The $σ(ω)$ spectr…
Based on a symmetry argument, we study ground states of what we call MMX-chain compounds, which are the new class of halogen-bridged metal complexes. Commensurate density-wave solutions of a relevant multi-band Peierls-Hubbard model are systematically revealed within the Hartree-Fock approximation. We numerically draw…
Electromechanical actuators based on sheets of single-walled carbon nanotubes were shown to generate higher stresses than natural muscle and higher strains than high-modulus ferroelectrics. Like natural muscles, the macroscopic actuators are assemblies of billions of individual nanoscale actuators. The actuation mecha…
The local environment and valence of copper ions in copper-doped magnesium oxide, (Mg 1 - x Cu x )O, were investigated under in situ conditions as a function of temperature T, composition x, and oxygen activity a O 2 . By comparison of Cu−K extended X-ray absorption fine structure (EXAFS) data with corresponding multi…
The hydrolysis of the spirotitanasiloxane Ti[(OSiPh 2 ) 4 O] 2 provides 1,1,3,3,5,5,7,7-octaphenyl-1,3,5,7-tetrasiloxane-1,7-diol, H(OSiPh 2 ) 4 OH ( 1 ), in high yield. The reaction of 1 with tricyclohexyltin hydroxide, cyclo -Hex 3 SnOH, and di- tert -butyltin oxide, cyclo -( t -Bu 2 SnO) 3, respectively, gives 1,1,…
A new macrocyclic ligand with a pendant naphthalene group, N-[2-(1-naphthyl)ethyl]-1-aza-4,8-dithiacyclodecane (L), has been synthesized and characterized. The copper(I)-acetonitrile complex [LCu(CH(3)CN)](PF(6)) (1) was synthesized from L and [Cu(CH(3)CN)(4)](PF(6)). The acetonitrile ligand from 1 was easily removed…
A self-assembly of a helical peptide in an aqueous medium was investigated in an attempt to compose a supramolecular structure. A peptide, HA16B, having a hydrophobic α-helical body and a hydrophilic polar head was synthesized and hydrated in water by sonication to obtain a transparent dispersion. Circular dichroism m…
Syntheses, structural studies, electrochemistry, and spectroscopy of a number of [5,10,15,20-tetrakis(heptafluoropropyl)porphinato]iron derivatives are presented. The X-ray crystal structure of 5,10,15,20-tetrakis(heptafluoropropyl)porphinato]iron(II)·(pyridine) 2 exhibits a substantial S 4 distortion of the porphyrin…
The preparation and characterization of several {FeNO} 6 porphyrinates ([Fe(OEP)(L)(NO)] + ), where OEP is octaethylporphyrin and L is one of the neutral nitrogen-donating axial ligands 1-methylimidazole (1-MeIm), pyrazole (Pz), indazole (Iz), or pyrazine (Prz), are described. The synthesis and crystallization of thes…
The analysis of a dendrimer of fifth generation by small-angle neutron scattering (SANS) in solution is presented. The contrast of the solute toward the solvent dimethylacetamide (DMA) is changed systematically by measurements of the dendrimer in mixtures of deuterated with protonated DMA. Additional SANS measurements…
Water-soluble poly(3-thiophene acetic acid) (P3TAA) and its copolymers with 3- n -methylthiophene or with 3- n -octadecylthiophene were synthesized. The solution properties of these water-soluble polythiophene carboxylic acids were studied by potentiometric titration, viscosity measurements, and UV−visible spectroscop…
The Burridge-Knopoff model of earthquake faults with viscous friction is equivalent to a van der Pol-FitzHugh-Nagumo model for excitable media with elastic coupling. The lubricated creep-slip friction law we use in the Burridge-Knopoff model describes the frictional sliding dynamics of a range of real materials. Low-d…
The synthesis, crystal structure, and magnetic characterization of a novel tetranuclear iron(III) methoxo-bridged cluster of formula Fe 4 (OCH 3 ) 6 (dpm) 6 (where Hdpm = dipivaloylmethane) is reported. The cluster has a ground spin state of S = 5, which is selectively populated below 20 K. High-field EPR spectra reve…