Iterative equations in Banach spaces

Let X be a Banach space, let

     

The first nonempirical circular dichroism determination of the absolute configuration of N-phthalimidosulfoximines based on exciton coupling mechanism and a correlation with the absolute configuration of chiral sulfoxides

A simple nonempirical method for the assignment of absolute configuration of N-phthalimidosulfoximines and related S-chiral sulfoxides, based on exciton-coupled circular dichroism, is presented.     

Mössbauer and magnetic characterization of TbRhSn

The intermetallic compound TbRhSn was investigated in detail by X-ray, magnetic susceptibility measurements and ¹¹⁹Sn Mössbauer spectroscopy. This compound undergoes a transition from a paramagnetic to an antiferromagnetic state at T _N = 20.8(2) K. The ¹¹⁹Sn Mössbauer spectrum recorded at 4.2 K can be well fitted as a composition of three subspectra with the same intensities, magnitudes of H _hf, ΔE _Q, and δ _is, in agreement with the model of triangular-like antiferromagnetic arrangements of equal magnetic Tb moments lying in the basal ab-plane deduced from neutron diffraction studies (Szytu?a et al., J Alloys Compd 244:94–98, 1996).     

Synthesis of Nucleotide Analogues with Pyridylphosphonate and Pyridylphosphono thio ate Internucleotide Linkages

Efficient synthetic methods for the preparation of dinucleoside 4-pyridyl-, 3-pyridyl-, and 2-pyridylphosphonates have been developed.     

Kinetics of Interfacial Polycondensation of Bisphenols with Isophthaloyl Chloride

Reaction rates of interfacial polycondensation of bisphenol A and chlorobisphenol II with isophthaloyl chloride were investigated. Rate constants and activation energies were determined The reaction rate was found to depend on stirring speed, catalyst, type of bisphenol, and temperature.     

Synthesis of (3R,5S,6R) 2,6-Diacetoxymethylclavam from D-Galactal

Abstract

N- (t-Butyl)dimethylsilyl-2- C: 1 - N- car bony 1 - 2 -deoxy- α-D-galactopyran-osylamine (1) was tritylated and the product was subjected to a glycolic cleavage to give dialdehyde 10. Subsequently, compound 10 was transformed into bromide 14 using standard procedures. The fluoride anion induced cyclization in 14 afforded clavam 15.     

Synthetic approaches to 9-arylated Cinchona alkaloids: stereoselective addition of Grignard reagents to cinchonanones and hydroxylation of 9-phenylcinchonanes

All 8,9-isomers of the 9-phenyl Cinchona alkaloids were obtained by autoxidation of 9-deoxy-9-phenyl-alkaloids and by the addition of Grignard reagents to the respective ketones. The diastereoselective addition of phenyl-, methyl-, and vinylmagnesium reagents to quinidinone and cinchoninone gave the corresponding (8R,9S)-products with acceptable yields and starting material recovery. The configurations of the compounds obtained were established by chemical correlations, NMR experiments, and were supported by DFT calculations and X-ray structures. Stereochemical models for both reactions were also devised and discussed.     

Radiation-induced synthesis of Fe-doped TiO2: Characterization and catalytic properties

Fe-doped TiO₂ catalyst was prepared by wet impregnation, using TiO₂ P25 Degussa as a precursor and Fe(NO₃)₃ as a dopant, followed by irradiation with an electron beam or γ-rays. Surface properties of Fe/TiO₂ samples were examined by BET, XRD, ToF-SIMS, and TPR methods. The photocatalytic activity towards destruction of the anionic surfactant, sodium dodecylbenzenesulfonate (SDBS), in aqueous solutions was higher for the irradiated Fe/TiO₂ catalysts than for bare TiO₂ P25 or that calcined at 500 °C. The results show that irradiated catalysts exhibit a more uniform texture with high dispersion of iron species. An enhancement of the activity of irradiated Fe/TiO₂ systems can be attributed to the synergetic effects of small crystallite size and homogenous distribution of iron species including FeTiO₃ phase.