Materials Literature
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Regioselective bromination of 2-nitro-5,10,15,20-tetraphenylporphyrin, cyclopropa[b]chlorins, or trans-bis(dicyanomethyl)chlorins occurs in the pyrrole subunit opposite the substituted ring; exhaustive bromination of functionalized tetraphenylchlorins provides a route to dodecasubstitued dihydroporphyrins for the firs…
A series of samples of MoO3 and/or ZnO supported on tetragonal ZrO2 (t-ZrO2) have been investigated by laser Raman spectroscopy and XRD. For these supported binary-oxide systems, the loading sequence of the oxide and the calcination temperature have notable effects on the interactions of the oxides and support and hen…
AE 1. AE (29). 2. AE AE (30). 2.1. AE. 2.2. AE AE - AE AE. 2.3. () AE. 3. AE (38). 3.1. AE. 3.2. AE. 4. AE AEAE (41). 4.1. AE . 4.2. - AE. 5. AE AE (45). 5.1. AE . AEAE . 5.2. . 5.3. AE AEAE . 5.4. . 5.5. . 5.6. AE-. 6. (52). (52). 1. AE AE AE AE - AE (
The crystal structure and absorption spectra (IR, UV/VIS) have been determined for Na0.5H5.5[Nd2(ttha)2]· 7.5NaClO4·16.83H2O (H6ttha = triethylenetetraaminehexaacetic acid). The structure consists of the complex dimer, perchlorate anions, sodium cations and water of hydration. Both neodymium(III) ions are nine-co-ordi…
We have used resonant reflection mode Fabry–Perot microcavities (RFPM’s) to determine linear optical and electro-optical properties of poled nonlinear optical polymers (NLP’s). Measured reflectances from angular scans of RFPM’s have been analyzed with an electromagnetic plane-wave multilayer analysis that took into ac…
The synthesis and characterization of a series of tetrathiafulvalenes (1–3) bearing a different number of 4′-cyanobiphenyl-4-yloxy side groups is reported. Compound 3 exhibits a nematic and a smectic A mesophase. In the smectic A phase a peculiar local biaxial order due to the unconventional molecular structure is pro…
The energy gap dependence of the rate of electron transfer has been revealed for donor–acceptor supramolecular assemblies composed of zinc–tetraphenylporphyrin and a series of spacer–acceptor conjugate molecules which are structurally similar but with varying redox potentials.
Abstract Blends of linear low‐density polyethylene (LLDPE) and linear low‐density polyethylene–grafted maleic anhydride (LLDPE‐gMA) were used to promote the adhesion to polyamide 6 (PA) in a three‐layer coextruded film without using an additional adhesive or tie layer. The effect of bonding time and molecular weight (…
Glauconite and Ca phosphate peloids occur in Jurassic and Cretaceous bioclastic carbonate rocks from pelagic swell sequences of the Algayat-Crevillente Unit (Subbetic Zone). The size and morphology of the peloids are controlled by the bioclasts. The glauconite in both stratigraphic positions is K rich (>0.69 atoms p.f…
The protonation constants of H2L1, 3,11-bis(carboxymethyl)-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),13,15-triene and H3L2, 3,7,11-tris(carboxymethyl)-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),13,15-triene, and stability constants of complexes formed by these macrocycles with Mg2+, Ca2+, Mn2+, Co2+, Ni2+…
Sixteen 1:1 methanesulfonic acid–N-oxide systems were studied as a function of the basicity of the N-oxides. The observed IR continua demonstrate that a single minimum proton potential is shifted, with increasing basicity, from the acid to the N-oxide. The largest proton polarizability is attained with the system that…
The hydrothermal reaction of a mixture of vanadyl acetylacetonate (VO(acac)(2)), Na(2)SO(4), 2,2'-bipyridine (2,2'-bpy), and H(2)O for 48 h at 160 degrees C gives brown crystals of [V(2)O(2)(OH)(2)(SO(4))(2,2'-bpy)(2)] (1) in 70% yield. The structure of 1 consists of ribbons constructed from the infinite inorganic cha…
The protonation constants of the ligand 1,7-dicarboxymethyl-1,4,7,10-tetraazacyclododecane (DO2A) were re-determined by the potentiometric pH titration method (log K 10.94, 9.55, 3.85, 2.55) and the macrocycle ring protonation sites have also been confirmed by NMR techniques to be the secondary amine nitrogen atoms. T…
Sulfonated manganese(III) tetraphenylporphyrin supported on poly(4-vinylpyridine), Mn(tpps)–PVP, can act as an efficient heterogeneous catalyst for alkene epoxidation and alkane hydroxylation by sodium periodate.
This paper deals with the plasma surface treatment of polymers in a low frequency bell jar reactor with non-symmetrical configuration of electrodes. This special configuration of electrodes simulates the industrial surface treatment of polymers i.e. very short treatment times (milliseconds to a few seconds). The physi…
By using an electrostatic probe located close to the triple junction on the cathode surface, we have conducted real-time observations of the change in electric field due to surface charging of an insulator in vacuum. A cylindrical sample made of polymethylmethacrylate (PMMA) or Al/sub 2/O/sub 3/ has been exposed to HV…
The study was conducted to determine whether living or killed cell polyphosphate bodies (PPB) would sequester more of several heavy metals. Living and heat- or glutaraldehyde-killed cells were exposed to 20 ppm of Zn, Pb, Mn and Al. Air-dried cells on Formvar-coated grids were first observed in the transmission electr…
The upper critical temperature ${T}_{c2}$ for the phase transition between the cholesteric phase ${(N}^{*})$ and the twist grain boundary $C$ phase with the layer inclination tilted to the pitch axis $({\mathrm{TGB}}_{\mathrm{Ct}})$ in thermotropic liquid crystals is determined by the mean field Chen-Lubensky approach…
It has been shown that the high catalytic activity of a Dawson-type heteropolyacid for gas-phase methyl tert-butyl ether synthesis at low temperatures is attributable to its amorphous secondary structure, which brings about a flexible pseudo-liquid phase and facilitates rapid absorption and desorption of molecules.
Cycles of wetting and blow-drying were applied to hair fibers and resulted in the formation of multiple cracks on the hair cuticles. The peculiarity of these cracks was that they always appeared aligned parallel to the longitudinal axis of the hair fiber. The cracks appeared to be initiated at the end of the cuticles…