Materials Literature
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The thermal and mechanical properties for four binary blends, high-density polyethylene (HDPE)–metallocene polyethylene (MCPE), polypropylene (PP)–MCPE, poly(propylene-co-ethylene) (CoPP)–MCPE, and poly(propylene-co-ethylene-co-1-butene) (TerPP)–MCPE were investigated to compare the compatibility and molecular microme…
Manganites with the perovskite structure represent a very important family of oxides which are extensively studied for their colossal magnetoresistance (CMR) properties. In the present review we discuss the different factors which govern the magnetic and transport properties of these materials: carrier concentration,…
Light-harvesting arrays containing one, two, or eight boron-dipyrrin (BDPY) pigments and one porphyrin (free base or Zn chelate) have been synthesized using a modular building block approach. The reaction of pyrrole and 4-(BDPY)benzaldehyde or 3,5-bis(BDPY)benzaldehyde, prepared by Pd-mediated ethynylation with the co…
Without any prior knowledge of the molecular structure, all 31 carbon and oxygen atoms of fluorescein diacetate were accurately located based on a high-resolution powder diffraction experiment. Direct methods and Fourier recycling were used. This represents a considerable advance with respect to the size of an organic…
The formation of a sitting-atop (SAT) complex of Cu(II) ion with 5,10,15,20-tetraphenylporphyrin (H(2)tpp) in acetonitrile has been observed, and the kinetic parameters for the formation were determined as follows: k(S0) = (3.6 +/- 0.1) x 10(5) mol(-)(1) dm(3) s(-)(1) at 25.0 degrees C, DeltaH(S0)() = 56 +/- 5 kJ mol(…
Double chelate coordination of [Cu(Ph3P)2]+ stabilizes the radical anion of 2,2′-azobis(5-chloropyrimidine), which exhibits a N–N bond length of 1.345(7) Å in the complex (see picture). This is consistent with a one-electron reduced azo functionality.
The introduction of different metal ions in specific positions is achieved in the synthesis of [2×2] grid-type heterometallic complexes (see schematic representation; the black bars symbolize the ditopic ligands, and the circles the different metals ions). This novel method for the construction of inorganic architectu…
Twenty-one components self-assemble to form the large (ca. 25 nm2), planar porphyrin arrays of type 1: four dipyridylporphyrins, four tripyridylporphyrins, one tetrapyridylporphyrin, and twelve PdCl2 units.
We give a simple demonstration of the formula relating the glass transition temperature, $T_g$, to the molar concentration $x$ of a modifier in two types of glasses: binary glasses, whose composition can be denoted by $X_nY_m+xM_pY_q$, with ^$X$ an element of III-rd or IV-th group (e.g. B, or Si, Ge), while $M_pY_q$ i…
Brownian motion of an array of harmonically coupled particles subject to a periodic substrate potential and driven by an external bias is investigated. In the linear response limit (small bias), the coupling between particles may enhance the diffusion process, depending on the competition between the harmonic chain an…
This review concerns the synthesis, characterization, and applications of porous manganese oxides during the last two years. The synthesis of porous tunnel structures, layered structures, and related materials is discussed. Both microporous and mesoporous systems materials are covered here. Characterization discussed…
Stereospecific 1 H and 13 C resonance assignments of hexadienoyl-CoA and crotonyl-CoA have been determined. The two diastereotopic methyl groups at the C2‘‘ carbon were assigned via transferred nuclear Overhauser effect experiments on the complex of hexadienoyl-CoA with the enzyme enoyl-CoA hydratase. The two diastere…
Site-directed mutagenesis was utilized to construct mutants, containing one or two tryptophan residues, of the bifunctional enzyme fructose 6-phosphate,2-kinase-fructose 2,6-bisphosphatase. Two of the single-tryptophan mutants (W15 and W64) had the tryptophan residue located in the kinase domain, which is in the N-ter…
We have discovered a novel procedure that yields extremely stable ruthenium-modified indium−hexacyanoferrate(II/III) film electrodes. The process includes electrochemical deposition of the indium(III)−hexacyanoferrate (InHCF) film and its subsequent voltammetric conditioning in 1 mM RuCl 3 . The resulting inorganic fi…
Phase separation of polystyrene derivatives (PSS) and poly(vinyl methyl ether) (PVME) mixtures was induced in the one-phase region by using photoisomerization of trans -stilbene moieties labeled on the PSS chains. The phase separation was monitored by phase-contrast optical microscopy and was analyzed using digital im…
Matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (TOF) mass spectrometry allowed direct determination of the extent of macrocycle formation that occurred during the polymerization and copolymerization of A 2 B and A 4 B monomers. Cyclization in hyperbranched pentafluorophenyl-terminated poly(benzyl e…
The typical island distance $\ell$ in submonlayer epitaxial growth depends on the growth conditions via an exponent $γ$. This exponent is known to depend on the substrate dimensionality, the dimension of the islands, and the size $i^*$ of the critical nucleus for island formation. In this paper we study the dependence…
The three-dimensional coordination polymers [{( n -C 4 H 9 ) 3 Sn} 3 M(CN) 6 ] (M = Fe, Co) were synthesized by slow interdiffusion of aqueous solutions of K 3 [M(CN) 6 ] and THF solutions of (C 4 H 9 ) 3 SnCl. The structures were determined by single-crystal X-ray crystallography (M = Fe, cubic, P 4 1 32, a = 17.338(…
Highly ordered macroporous materials with uniform pore size of the micrometer scale are known to have important technological uses such as photonic band-gaps and optical stop-bands. However, they can only be produced through adequate treatment of ordered monodisperse macroemulsions. Here, we report how a small amount…
A synthetic strategy has been developed for preparation of NLO chromophores with all the π-conjugated methine groups incorporated into plane-rigidified, fused, six-membered rings. The comparison of the rigidified chromophores to the analogous nonrigid chromophores shows that the configuration-locking methods provide a…