Materials Literature
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Chirality from the crystal lattice: The achiral diarylethene 1 a crystallizes in a monoclinic chiral space group, that is, two different kinds of crystals, (M)-1 a and (P)-1 a, are obtained. Photoirradiation of (P)-1 a furnished optically pure closed-ring isomer (R,R)-1 b in the single crystal (see scheme). The photoc…
Optical measurements of the shear response of semidilute dispersions of polymer-dispersed multiwalled carbon nanotubes are presented. For a weakly elastic polymer melt, the data suggest that the semiflexible tubes orient along the direction of flow at low shear stress, with a transition to vorticity alignment above a…
Thin films of polystyrene (PS) and poly(methyl methacrylate) (PMMA) were spun-cast onto silicon substrates, annealed, and analyzed by atomic force microscopy (AFM), total electron yield (TEY), and partial electron yield (PEY) near-edge X-ray absorption fine structure (NEXAFS) spectroscopy in order to resolve conflicti…
The synthesis, luminescence properties, experimental determination and theoretical calculation of the emission quantum yield of Eu(NTA)3.2L complexes, where NTA is naphtoiltri-fluroacetone and L denotes H2O or DMSO (dimethyl sulphoxide), were reported. The compounds were characterized by elemental analysis (carbon, hy…
Bi 3.35 La 0.75 ( Ti 1−x W x ) 3 O 12 (BLTW) and Bi3.35La0.75(Ti1−xMox)3O12 (BLTM) (x=0.3%, 0.5%, 1%, and 2%) films were fabricated on Pt/Ti/SiO2/Si〈100〉 structures by a sol-gel method at 750 °C. The B-site substitution with high-valent cations, W6+ or Mo6+, in Bi3.35La0.75Ti3O12 (BLT) enhanced the remanent polarizati…
A (polymer network/nematic liquid crystal/chiral dopant) composite exhibiting a chiral nematic (N*) phase at room temperature has been developed. Because the helical twisting power of the chiral dopant increases with increasing temperature and the polymer network affects the molecular rearrangement of the liquid cryst…
CdSe nanocrystal thin films exhibit stable and quantitative electrochemical responses when treated with cross-linking molecules such as dithiols or diamines. For the first time, a voltammetric response is recorded for the reduction of the nanocrystals with quantitative injection of electrons in the 1S e state. Injecti…
Meissner fraction in the superconducting state of lead archaeological artifacts is used to evaluate the mass of the uncorroded metal in the sample. Knowing the total mass of the sample the mass of all corrosion products is established. It is shown that this mass correlates with the archaeological age of the lead artif…
We argue that the presence of dissociated ions in block copolymers under electric fields can induce strong morphological changes and even lead to phase transitions. We investigate, in particular, diblock copolymers in the body centered cubic (bcc) phase. In pure dielectric materials (no free charges), a dielectric bre…
Spin doctoring: [FeIIH3L][FeIIIL](NO3)2, where H3L is a hexadentate tripod ligand bearing three imidazole groups, is formed in a one-pot assembly reaction, and is shown to be a homochiral mixed-valence spin-crossover compound. The structure consists of a 2D assembled sheet that is held together by imidazole–imidazolat…
Scanning tunneling microscopy can be utilized to individually probe single-molecule magnets that have been deposited on gold substrates (see schematic). Dilute solutions (in THF/H2O/NH4OH) of a dodecamanganese(III,IV) cluster surrounded by acetyl-protected thiol groups, [Mn12O12(L)16(H2O)4], have been used to prepare…
Three new luminescent and redox-active Ru(II) complexes containing novel dendritic polypyridine ligands have been synthesized, and their absorption spectra, luminescence properties (both at room temperature in fluid solution and at 77 K in rigid matrix), and redox behavior have been investigated. The dendritic ligands…
The electronic properties of the cleavage InAs(110) surface are studied using a semi-empirical tight-binding method which employs an extended atomic-like basis set. We calculate the surface electronic band structure which is studied as a function of the structural parameters of the surface. We describe and discuss the…
Atomic models of zigzag (n, 0)- and armchair (n,n)-like NiCl2 nanotubes (n = 4 - 29) formed by rolling (100) single layers of the bulk NiCl2 which crystallizes in the CdCl2-type structure, are constructed and their electronic properties and bond indices are investigated using the tight-binding band theory. The calcula…
We have demonstrated that a simply prepared water-soluble polyoxometalate, Na12[WZnZn2(H2O)2(ZnW9O34)2], synthesized from readily available zinc and tungsten salts in the presence of nitric acid, is an effective catalyst for selective alcohol oxidation with hydrogen peroxide in biphasic (water-alcohol) reaction media.…
An energetic analysis of the thermal decomposition of solid urea and urea solutions is presented, and the results are discussed in view of urea selective catalytic reduction (SCR) for automotive DeNOx systems. Various types of decomposition reactors are possible which differ in their effectiveness to produce ammonia f…
Ductile metals and alloys undergo plastic yielding at room temperature, during which they exhibit work-hardening and the generation of surface instabilities that lead to necking and failure. We show that pure nanocrystalline copper behaves differently, displaying near-perfect elastoplastic behavior characterized by Ne…
In this paper, copper nanocrystals are produced by using Cu(AOT) 2 −isooctane−water solution as a template. Even if the template does not change with various salt additions, the nanocrystal growth markedly depends on the salt used. It is demonstrated that chloride ions enable the growth of nanorods with an aspect rati…
A series of extraordinarily long oligothiophenes up to the 96-mer has been developed by iterative oxidative coupling of the completely beta-blocked sexithiophene. They are highly conjugated like nonsubstituted oligothiophenes, and the effective conjugation of this system is extended to 96 thiophene units and much long…
Graphite intercalation compounds are a new class of electronic materials that are classified as graphite-based host guest systems. They have specific structural features based on the alternating stacking of graphite and guest intercalate sheets. The electronic structures show two-dimensional metallic properties with a…