Materials Literature
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The structure of the alpha-(Al,Si)CuFe approximant phase is determined by a single-crystal X-ray diffraction study and compared to the ideal structure obtained by the perpendicular shear method of the parent icosahedral phase. It is shown that the local environments (typical atomic clusters) of the two phases are simi…
Abstract Catalysis in electron transfer reactions between electron donors and acceptors is described and the important mechanistic insight is provided by showing a number of examples of both thermal and photochemical reactions that involve metal ion‐catalyzed electron transfer processes as the rate‐determining steps.…
The phase behaviour of a binary polymer blend of polyethylene glycol (PEG600) and polypropylene glycol (PPG1000) of low polydispersity was investigated. The coexistence curves of five different compositions, including the critical composition, were measured by differential refractometry. From the coexistence curves, t…
Abstract Carboxylic acid chloride end‐functionalized all‐aromatic hyperbranched polyesters were prepared from the bulk polycondensation of the AB 2 monomer 5‐(trimethylsiloxy)isophthaloyl dichloride. The acid chloride end functionality of the hyperbranched polyester was modified in situ with methanol and yielded methy…
Thirty years ago, automotive engineers perfected real-time damping for vehicle suspension systems prior to hitting bumps in the road. In the near future, architects and structural engineers may be able to use the same philosophy for tuning structures to withstand earthquakes as their waves impinge on the structure. Co…
1,4-Bis-(α-cyano-4-methoxystyryl)benzene (1a) and 1,4-bis-(α-cyano-4-methoxystyryl)-2,5-dimethoxybenzene (1b) were synthesized by the Knoevenagel reaction of (4-methoxyphenyl)acetonitrile with terephthaldicarboxyaldehyde and 2,5-dimethoxy terephthaldicarboxyaldehyde, respectively. Both phenylene vinylene oligomers are…
By copolymerization of 3-octylthiophene with thiophene containing aniline tetramer in the 3-position we have prepared a hybrid copolymer, poly(3-octyl-2,5-thienylene- co -3-oligoaniline-2,5-thienylene), exhibiting very interesting spectroscopic and spectroelectrochemical properties. The UV−vis−NIR spectrum of this new…
Energy-filtered Debye-Scherrer electron powder data have been successfully employed to determine the structure of nanocrystalline anatase (TiO2). The performed structure analysis includes determining the unit cell, space group, solving the structure via direct methods from extracted intensities and refining the struct…
A novel Ru(II) complex possessing two sequentially linked viologen units, Ru-V(1)-V(2)(6+), was synthesized and characterized. Upon excitation of the Ru(II) unit (lambda(exc) = 532 nm, fwhm approximately 10 ns), a long-lived charge-separated (CS) state is observed (tau = 1.7 micros) by transient absorption spectroscop…
The X-ray structure of the blue phototautomer of 2-(2',4'-dinitrobenzyl)pyridine (DNBP) produced by two-photon excitation in a single crystal is the first direct evidence of a product in the DNBP photochromic family. A nitro-assisted proton transfer mechanism is attributed to the photocoloration of solid DNBP.
A hyper-frequency method enabling to investigate into the bubble size distribution of a bubble cloud in which bubble radii are lower than the equilibrium one is displayed. It is based on analysing the void rate dissipation after the acoustic irradiation is switched off in terms of bubble dissolution. The experimental…
Thermolysis of gold(I) thiolate complex, [C14H29(CH3)3N][Au(SC12H25)2], at 180 degrees C for 5 h under an N2 atmosphere produces novel gold nanoparticles passivated by alkyl groups derived from the precursor complex, the TEM image of which shows spherical particles with average diameter 26 nm.
Analytical expressions in the time and frequency domains are derived for non-Debye relaxation processes. The complex frequency-dependent susceptibility function for the stretched exponential relaxation function is given for general values of the stretching exponent in terms of H-functions. The relaxation functions cor…
A novel heterospin system, [(CuL)2Gd(TCNQ)2].TCNQ-.CH3OH.2CH3CN, is obtained by reacting the mononuclear complex, [CuL], with gadolinium(III) nitrate, followed by the substitution of the nitrato ions with anionic organic radicals.
The development of new techniques such as the molecular beam epitaxy have enabled the growth of thin films of materials presenting novel properties. Recently it was made possible to grow a CrAs thin-film in the zinc blende structure. In this contribution, the full-potential screened KKR method is used to study the ele…
Time-resolved optical spectroscopy of collective and single-particle excitations of $1T\ensuremath{-}{\mathrm{TaS}}_{2}$ and $2H\ensuremath{-}{\mathrm{TaSe}}_{2}$ reveals the presence of a large gap in the excitation spectrum on the femtosecond time scale, associated with the formation of various degrees of charge-den…
Syntheses, optical spectroscopy, potentiometric studies, and electronic structural calculations are reported for two classes of conjugated (porphinato)metal oligomers that feature a meso-to-meso ethyne-bridged linkage topology. One set of these systems, bis[(5,5'-10,20-bis[3,5-bis(3,3-dimethyl-1-butyloxy)phenyl]porphi…
The performances of oxidation and SCR catalysts were investigated individually and as a combined system for the removal of NO x by ammonia. Experiments were carried out with synthetic gas mixtures matching the composition of diesel exhaust. Introducing an oxidation catalyst upstream of the SCR catalyst enhances the re…
In this paper, treatment of 1,1'-(1,4-butanediyl) bis-1H-benzotriazole (bbbt) and KSCN with Co(II), Mn(II), or Cd(II) afforded three two-dimensional rhombohedral grid coordination polymers [M(bbbt)(2)(NCS)(2)](n)(M = Co, 1; Mn, 2; Cd, 3). The two-dimensional rhombohedral grids are parallel to the crystallographic ac p…
Intracellular Ca(2+) plays an important role in signal transduction, and we are developing new MRI techniques to study its regulation in living animals. We have reported on an MRI contrast agent (DOPTA-Gd) where the relaxivity of the complex is controlled by the presence or absence of the divalent ion Ca(2+). By struc…