Materials Literature
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In methanol, the defect nitrosylpolyoxomolybdate [Mo5O13(OMe)4(NO)]3– reacts with Ag+ to give the complex [Ag2{Mo5O13(OMe)4(NO)}2]4– which displays attractive interactions between the two square-planar closed-shell AgI cations.
Optically active ‘adjacent’ type non-centrosymmetrically substituted phthalocyanines (Pcs) and benzo-substituted Pcs having π-systems with C2v symmetry have been synthesized in high yields in a mixed condensation using bisphthalonitriles (which do not racemize under general Pc formation conditions) and a second phthal…
Spectrophotometric pKa determination for p-tert-butylcalix[5]arene (H5L) in acetonitrile (pKa1 = 11.5 ± 0.7, pKa2 = 15.4 ± 1.0 at 298 K) evidenced both intra- and inter-molecular stabilisation of the deprotonated forms. Dimeric complexes [Ln2(H2L)2(dmso)4] (Ln = EuIII, GdIII, or TbIII; dmso = dimethyl sulfoxide) were…
The salts of the tetranuclear vanadium(III) ions [V4O2(O2- CEt)7(L–L)2]z (L–L = bpy, z = +1; L–L = pic–, z = –1) with a V4 butterfly topology and a S = 3 ground state have been found to exhibit out-of-phase ac susceptibility signals, a signature of single-molecule magnets.
Cs 2.5 H 0.5 PW 12 O 40, a hydrogen cesium salt of dodecatungstophosphoric acid, exhibited a high catalytic activity for hydrolysis of ethyl acetate in large excess water. Adsorption of water demonstrated that interactions between Cs 2.5 H 0.5 PW 12 O 40 and water are weak. This nature and the strong acidity are possi…
A novel cationic delivery system composed of magnetic aminodextran microspheres (MADM) 1-2 microm in diameter was evaluated along with neutral magnetic dextran microspheres (MDM) for their ability to target intracerebral rat glioma-2 (RG-2) tumors in vivo. The tissue distribution of the microspheres was determined fol…
TOPO (tri-n-octylphosphine oxide)-capped ZnSe (in the form of close to mono-dispersed nanoparticles) has been prepared by a single source route using ethyl(diethyldiselenocarbamato)zinc(ii) as a precursor. The nanoparticles obtained show quantum size effects in their optical spectra and exhibit near band-edge luminesc…
Pentafluorothiophenol, thiophenol, 1-decanethiol, 1-hexanethiol, benzoic acid and cyanoacetic acid, which are confirmed to bind to the surface of ZnS nanocrystallites, induce phase transition of ZnS nanocrystallites from the hexagonal to the cubic phase, with retention of the crystalline size of 3 nm at ambient temper…
The preparation of polyurethane capsules by interfacial reaction of di- and multiisocyanates (dissolved in toluene) and different di- and triols (dissolved in the aqueous phase) is investigated. Particular attention was paid to obtaining high yields and good mechanical resistance. The experimental conditions were chos…
Acid rain causes one of the more severe environmental contaminants, and there is an increasing interest in the degradation of outdoor polymer insulating materials in severe pollution conditions such as acid rain. The performance of high temperature vulcanizing (HTV) silicon rubber insulators in accelerated aging of ar…
Six Na-saturated smectites were isolated from bentonites of various deposits. Their H-forms were prepared using H–OH–H resins. The interaction of methylene blue (MB) (0.05 mmol g-1) with Na-saturated untreated and H-autotransformed clay samples was investigated by the VIS spectroscopy of their dispersions. The spectra…
The XPS spectra of corrundum were collected with a VSW HA150 using monochromatic Al Kα x-radiation. Monochromatic radiation provides a distinct clarity to the peak structure in the valence band of corrundrum due to the absence of interfering x-ray satellites from the intense O 2s region. Variations in the intensities…
The dependence of the surface-enhanced Raman scattering (SERS) of pyrazine (pz), adsorbed on polycrystalline gold electrodes (“smooth” and rough), on both the surface coverage and morphology was investigated. The morphology of the rough gold electrode was observed by atomic force microscopy (AFM), and the surface cove…
xBiFeO 3 -(1-x)BaTiO 3 form substitutional ferroelectromagnetic solid solutions with the rhomobohedral distortion up to 67% of BiFeO 3 . The paper reports data on phase formation, electrical conductivity anti dielectric constant as a function of temperature and frequency for the samples with x = 0.9 and 0.8 which are…
An influence of the alloy content of nickel and silicon on the precipitation kinetics and precipitation hardening mechanism in Cu-Ni-Si alloys has been studied.The degree and the rate of precipitation and the hardness change in the precipitation process increase with increasing an alloying elements. The degree and the…
Is it possible to make artificial materials that match or exceed the “hardness” of the two hardest known materials – diamond and cubic boron nitride? This question has long been of both basic and technological interest. Considerable excitement therefore greeted the recent theoretical prediction that the short, strong…
Zinc oxide nonlinear resistors with double the conventional reference voltage gradient, while improving their protective characteristics and raising discharging capability, were developed and applied to tank-type surge arresters. On the basis of high-performance elements, which provide good protective characteristics,…
The synthesis of 1a·(32 – n)Na+·ca. 600 H2O·ca. 30 CH3OH 1 containing the ring-shaped, mixed-valence (MoV/MoVI) cluster [(MoO3)176(H2O)63(CH3OH)17Hn](32 – n)– 1a as a discrete unit in the crystal lattice is reported, which for the first time yields a compound of this type via a facile synthetic method and without amor…
Starting from 1,4:3,6-dianhydrosorbitol (DAS, 1), a five step monomer synthesis led to 2-deoxy-1,4:3,6-dianhydro-2-isocyanato-L-iditol, 9, which by catalytic polyaddition gave polyurethane 13. A second route required the synthesis of 2-azido-5-O-chloroformyl-2-deoxy-1,4:3,6-dianhydro-L-iditol, 11. During catalytic hyd…
We have synthesized nine novel porphyrin derivatives, 1-8 and 1-Cu, substituted with various steric hindrance groups and long flexible chains in order to investigate the relationship between the molecular type of porphyrin derivatives and the resulting mesophase. Type 4 disc-like (C 12 O) 16 -TTPH 2 (1) and (C 12 O) 1…