Preparation of chiral indenes containing β-pinenyl derived ligand substituents

A simple procedure for the preparation of new 1-, 2- and 1,3-chirally substituted indenes is described in which indenyllithium or 2-indenylmagnesium bromide is reacted with a β-pinenyl derived chlorosilane. Synthesis of the ethylene bridged bis(indene) analogues of two of the new compounds is also described.     

Fe Mössbauer spectroscopic studies on M(CO)5(azaferrocene) complexes (M = Cr, Mo, W). The crystal structures of W(CO)5(azaferrocene) and W(CO)5(2,5-dimethylazaferrocene)

⁵⁷Fe Mössbauer spectroscopic studies on M(CO)₅(azaferrocene) complexes (M = Cr, Mo, W) as well as the crystal structures of W(CO)₅(azaferrocene) and W(CO)₅(2,5-dimethylazaferrocene) are reported. The complexation of azaferrocene to the M(CO)₅ moiety brings about only a small change in the quadrupole splitting. The structures of both tungsten complexes reveal a significant shortening of the W-C bonds trans to the nitrogen. These data indicate that azaferrocene behaves as a relatively strong σ-donor and there is no evidence for any π-acceptor properties.     

MEASUREMENT OF THE RATE OF UPTAKE AND SUBCELLULAR LOCALIZATION OF PORPHYRINS IN CELLS USING FLUORESCENCE DIGITAL IMAGING MICROSCOPY

Abstract A fluorescence imaging system incorporating a cooled slow-scan charge-coupled device camera was used to study the rate of uptake and subcellular localization of porphyrins in living cells. Measurements were carried out on human dermal fibroblasts (D532) using two different porphyrins meso -tetra(4- N -methylpyridyl)porphine (TMPP) and meso -tetra(4- N -hexylpyridyl)porphine (THPP). It was observed that TMPP was rapidly taken up by cells and principally located in the nucleus. The THPP, on the other hand, internalized more slowly and exhibited a particulate distribution in the cytoplasm.     

Fluorine-induced chemiluminescence detection of biologically methylated tellurium,selenium, and sulfur compounds

Summary The sensitive detection of volatile, methylated selenium and tellurium compounds based on capillary gas chromatography coupled to fluorine-induced chemiluminescence detection is described. The method requires no sample derivatization, and the detection limits for selenides and tellurides (low pg range) are the lowest reported to date. This technique can resolve and speciate complex mixtures of methylated tellurium, selenium, and sulfur gases and is useful for analysis of selenium and tellurium gases in environmental samples that also contain usually interfering reduced sulfur gases. Applications of the technique for analysis of bacterial and fungal headspace samples are presented.     

Many-body perturbation theory applied to hydrogen fluoride

Pair contributions to the electronic correlation energy of the hydrogen fluoride molecule are computed using many-body perturbation theory (MBPT) with a basis set of Slater orbitals on both atomic centers. Summation of all two-body diagrams through third order gives ≈ 93% of the total correlation energy at the equilibrium internuclear separation. However, including certain higher-order effects, by means of denominator shifts, gives a correlation energy of ?0.3691 hartree, or ≈ 97% of the correlation energy.     

Two predominance-region diagrams for plutonium

Two predominance-region diagrams for plutonium are illustrated. One diagram plots the pH vs. the equilibrium fraction of hexavalent plutonium. The other diagram plots the equilibrium fraction of tetravalent plutonium vs. the plutonium oxidation number. Both diagrams define the boundaries of the regions where tri-, tetra-, penta-, and hexavalent plutonium are the predominant species. In each diagram, the two principal triple points are located at the intersections of three predominance-region boundary lines.Los Alamos National Laboratory is operated by the University of California for the U.S. Department of Energy under Contract No. W-7405-ENG-36.     

ESR of Cu(II) in powders and single crystals of di-barium zinc formate tetrahydrate

ESR spectra of ⁶³Cu(II) doped powders were measured in the X-band and the Q-band, in the temperature range 15 to 293 K. The g-values at 15 K are 2.400, 2.090 and 2.065, ±0.002. The two higher g-values vary with temperature, the third one (2.065) being constant. The hyperfine tensor for ⁶³Cu was also studied. Preliminary data on ¹⁷O hyperfine couplings in single crystals of ⁶³Cu-doped formate are presented.     

Equilibrium method for estimating the first hydrolysis constant of tetravalent plutonium

A new method for estimating the numerical value of the first hydrolysis constant of tetravalent plutonium is illustrated by examples. It uses the pH and the equilibrium fractions of two of the Pu oxidation states. They are substituted into one or more of a choice of formulas that render explicit estimates of the hydrolysis constant.