Materials Literature
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1. Absorption and Photoluminescence in Porous Silicon 2. In-Situ Optical Investigations of Porous Silicon Immersed in Liquids 3. Electroluminescence from Porous Silicon in Contact with a Liquid Electrolyte 4. Nonlinear Optical Properties of Porous Silicon 5. Silicon Based Nanostructures 6. Optical Properties of Relate…
Two types of new nonlinear optical polymers have been synthesized by postreaction of an epoxy-based polymer prepared from the diglycidyl ether of bisphenol A and aniline. The new polymers DGEBA-AZO-TCV and DGEBA-AN-TCV were synthesized by azo coupling of the epoxy polymer with 4-(tricyanovinyl)aniline and by reacting…
Examples are given of transition-metal co-ordination complexes that give rise to alternating layers of organic and inorganic moieties in the solid state exhibiting finite zero-field magnetisation at low temperature. The mechanisms of magnetic exchange included are ferromagnetism, ferrimagnetism and canted antiferromag…
For the first time, electrospray ionisation mass spectrometry has been carried out on purely aqueous solutions of anions, specifically dilute (10–3 mol dm–3) isopolytungstates, peroxotungstates and heteropolymolybdates and tungstates. Many new species have been detected that have not previously been reported in water,…
Various particle sizes of starting barium titanate were used to investigate the effect of chemical inhomogeneity on the dielectric temperature characteristics of a dilute solid solution of cerium‐modified barium titanate. Transmission electron microscopy and energy dispersive spectroscopy confirmed three distinct area…
The synthesis and liquid-crystalline properties of a first-generation dendritic core substituted with six mesomorphic ferrocene units are reported; the investigated compound exhibited a broad enantiotropic smectic A phase (polarized optical microscopy, DSC, and XRD studies) and good thermal stability (thermogravimetry…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTEnantioselective Epoxidation of ω-Bromo-2-methyl-1-alkenes Catalyzed by Chloroperoxidase. Effect of Chain Length on Selectivity and EfficiencyFrederick J. Lakner, Kevin P. Cain, and Lowell P. HagerView Author Information Department of Biochemistry University of Illinoi…
In an attempt to prepare chiral discotic liquid crystals based on a helically twisted triphenylene nucleus a route has been developed for the introduction of α-fluoro, -chloro and -bromo substituents and it is shown that multiple α-halogenation is also possible. The monosubstituted derivatives all show enhanced mesoph…
Micrometre-sized, polypyrrole-coated polystyrene latexes with various conducting polymer loadings have been extensively characterized using X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectroscopy (TOF-SIMS), Raman and UV–VIS reflectance spectroscopy, scanning force microscopy (SFM) and s…
We study the phase behavior of ternary blends of A- and B-homopolymers and symmetric, or slightly asymmetric, AB-diblock copolymer as obtained from self-consistent field theory. We choose one value of the segregation in the weak to intermediate regime and determine the effects of varying the relative degrees of polyme…
The hydrothermal reaction of MoO 3 , Mo metal, NiCl 2 and 4,4′-bipyridine yields a step-layered molybdenum oxide [4,4′-H 2 bpy)][Mo 7 O 22 ]·H 2 O, a material structurally related to layered MoO 3 .
The reaction of ZnEt 2 with HO(O)P(O t Bu) 2 gives the insoluble polymer {Zn[O 2 P(O t Bu) 2 ] 2 } n ( 1 ). In the presence of slight amounts of water, this reaction produces good yields of the oxo-centered tetranuclear cluster Zn 4 (μ 4 -O)[O 2 P(O t Bu) 2 ] 6 ( 2 ), which has been characterized by X-ray crystallogra…
Interest in organic photocells was significantly renewed a few years ago due to discovery of extremely fast photo-induced charge transfer (CT) from conducting polymer (CP) to fullerene C/sub 60/ molecules in CP(C/sub 60/) composites. This allowed creation of interfacial junction photocells with relatively high efficie…
A highly ordered organic inorganic nanocomposite can be synthesized by photopolymerizing an inverse hexagonal lyotropic liquid crystal phase consisting of an amphiphilic monomer and organic crosslinker as the organic matrix and a sol‐gel silica precursor solution as the hydrophilic component (see Figure). In situ sili…
meso-Arylporphyrins participate, as dienophiles, in Diels–Alder reactions with o-benzoquinodimethane to yield novel chlorins, bacteriochlorins and naphtho[2,3-b]porphyrins.
The polyhedral arrangements in xTiO 2 .(1-x)P 2 O 5 (0.55≤x≤0.70) and yTiO 2 .(1-y)Ca(PO 3 ) 2 glasses have been characterised by Raman spectroscopy electron spin resonance (ESR) spectroscopy and solid state 31 P magic angle nuclear magnetic resonance (MAS NMR) spectroscopy In the binary titanophosphate glasses, struc…
Self-assembly of U-shaped 1,3-dialkylbenzimidazolium salts through hydrogen bonds and interdigitation of alkyl chains produces a bilayer structure with lamellar α and β mesophases.
We calculate the scattering spectra of weakly charged, randomly cross-linked polymer gels in poor and in ϑ solvents. For some values of the thermodynamic parameters, the competition between poor solubility, electrostatics, and network elasticity leads to the divergence of the structure factor at a wave vector q *, sig…
Two new series of racemic dimeric liquid crystals containing terminal alkyl chains with methyl branches are presented; in one the dimers are symmetric and in the other they are non-symmetric. Comparisons are made with the structurally isomeric series with no methyl branches in their terminal alkyl chains. The stabilit…
The aerobic epoxidation of alkenes with 2-methylpropanal can be carried out under fluorous biphasic conditions, in the presence of the perfluorocarbon soluble cobalt complex of tetraarylporphyrin 3 as catalyst.