Materials Literature
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Replacement of Na + by Li + has been achieved for sodalites of composition Na 8 [GaSiO 4 ] 6 X 2 and Na 8 [AlGeO 4 ] 6 X 2, where X is a halide, via nitrate melt at 240 °C. The resultant materials have been analyzed by Rietveld analysis of neutron powder diffraction data, and the derived structural parameters are comp…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTRing-Opening Copolymerization of (R)-β-Butyrolactone with Macrolide: A New Series of Poly(Hydroxyalkanoate)sYoji Hori, Hideyuki Hongo, and Toshimitsu HagiwaraView Author Information Central Research Laboratory, Takasago Internationa…
A method for the quantitative analysis of two-dimensional small-angle X-ray scattering (SAXS) patterns with fiber symmetry is proposed and applied to a series of images recorded during straining and relaxation cycles of a two-phase polymer sample at a synchrotron beamline.The studied longitudinal scattering originates…
A series of polybutadiene star polymers were produced by coupling living poly(butadienyl)lithium with dendritic chlorosilane linking agents. The theoretical arm numbers of the stars covered the range from 4 to 64, and the arm molecular weight was kept short with M n(arm) = 10 3 . MALDI-TOF MS and 1 H NMR spectroscopy…
The (hyper)polarizabilities obtained from the two valence bond state model including nonequilibrium solvation are compared to experiment. Specifically, the values of μ g 2 α zz (0) and μ g β zzz (0) in different solvents calculated from the model are compared to experimental measurements for several push−pull polyene…
A new open-framework zinc phosphate, [NH 3 (CH 2 ) 2 NH(CH 2 ) 2 NH 3 ] 2+ 2[Zn 2 PO 4 (HPO 4 )] -, possessing a layered architecture and consisting of alternating inorganic and organic layers, stabilized by multipoint hydrogen bonding has been synthesized hydrothermally. It has the following crystal data: monoclinic…
Single-crystal EPR studies of the Fe−O−Fe dimer, [enH 2 ][{Fe(HEDTA)} 2 O]·6H 2 O, have been performed at both X- and Q-band frequencies and room temperature. Resonances arising from the S‘ = 1, 2, and 3 states have been observed in the powder spectrum at Q-band frequency and analysis by spectral simulation has led to…
The chemical potential of adsorbed film inside cylindrical mesopores is dependent on the attractive interactions between the adsorbed molecules and adsorbent, the curvature of gas/adsorbed phase interface, and surface tension. A state equation of the adsorbed film is proposed to take into account the above factors. Ni…
A series of nanocrystalline solid solutions (CeO 2 ) 1 - x (BiO 1.5 ) x ( x = 0.0−0.5) were synthesized by mild hydrothermal conditions at 240 °C. The products were characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonanc…
A series of mesoporous vanadosilicate V−MCM-41 molecular sieves with variable Si/V ratios have been synthesized at room temperature using a minimum amount of template. The chemical environment of the vanadium centers in V−MCM-41 was investigated by powder X-ray diffraction (XRD), transmission electron microscopy (TEM)…
Liq. crystals displaying a Colh (columnar hexagonal) phase can display a cooperative chiral state. In the authors model the hexagonal symmetry is an integral feature that favors the chiral state. This latter point is also supported by the recent work on fluxional 8 vertex Zr4+ mesogens (Trazaska et al. 1999) with the…
The Fur apoprotein has been purified and reconstituted with Co2+ and Mn2+ ions. These samples have been analyzed by UV-visible, EPR, and 1H NMR spectroscopies, by XAS, and by magnetization measurements. The apo-Fur protein is able to bind one metal dication (Co2+ or Mn2+) per monomer. A saturation magnetization study…
Accurate measurements of the height and position of the preedge peak in Ti K-edge XANES (X-ray absorption near-edge structure) can distinguish 4-, 5-, and 6-fold coordination of Ti by O ( [4] Ti, [5] Ti, and [6] Ti, respectively), and mixtures thereof. This approach has been applied to titania−silica xerogels, (TiO 2…
Melt condensation of 1,5-bis(9-hydroxy-1,4,7-trioxanonyl)naphthalene ( 2 ) with bis-acid chlorides, adipoyl chloride ( 3a ), terephthaloyl chloride ( 3b ), and 3,6,9,12-tetraoxatetradecane bis-acid chloride ( 3c ), respectively, gives amorphous linear poly(ether−ester)s 1a − c, which contain 1,4,7-trioxanonyl (triethy…
This paper presents the rheology and morphology of immiscible polymer blends compatibilized by a polymer reaction at the interface. Nylon-6 was melt blended in a twin screw extruder with several different grades of maleated polypropylene at 10 and 20 wt %. The extent of polymer reaction at the interface is varied by v…
Aluminosilicate MCM-41 mesophase solids have been prepared under alkaline conditions with high degrees of mesoscopic order and silicon-to-aluminum molar ratios approaching unity. One- and two-dimensional solid-state NMR techniques, in conjunction with elemental analyses, infrared spectroscopy, and powder X-ray diffrac…
The complexes [Cu 2 (dpt) 2 Cl 2 ]X 2 (dpt = dipropylenetriamine; X = Cl, 1; X 2 = (Cl)(BPh 4 ), 2 ) have been prepared and their magnetic properties studied. The crystal structure of complex 1 has been solved. The compound belongs to the C 2/ c space group with Z = 4, a = 17.201(2) Å, b = 10.873(2) Å, c = 11.835(2) Å…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSquare and Triangular Arrays Based on Mo24+ and Rh24+ UnitsF. Albert Cotton, Lee M. Daniels, Chun Lin, and Carlos A. MurilloView Author Information Department of Chemistry and Laboratory for Molecular Structure and Bonding P.O. Box 30012, Texas A&M University College S…
Well-dispersed platinum colloids have been prepared on polystyrene nanospheres with surface-grafted poly( N -isopropylacrylamide) (PNIPAAm) via the reduction of PtCl 6 2 - by ethanol. A range of monodisperse nanospheres was obtained by emulsifier-free dispersion copolymerization of styrene with a PNIPAAm macromonomer.…
Three different multicomponent molecular systems have been synthesized by means of the three-dimensional template effect of copper(I). These systems incorporate both a coordinating ring (2,9-diphenyl-1,10-phenanthroline-containing 30-membered ring) and a molecular string which consists of two different coordination si…