Spectroscopic studies of solutions,suspensions, and precipitates of poly(1,6-di-p-toluene sulfonyloxy-2,4-hexadiyne)

Optical-absorption, fluorescence, and Raman spectra for solutions, suspensions, and precipitates of poly(1,6-di-p-toluene sulfonoxy-2,4-hexadiyne) in and from nitrobenzene, acetone, and chloroform are presented. These are interpreted in terms of the occurrence of two forms of the polymer chain; a quasicrystalline form with properties close to those of single crystal polymer and a chain-extended form occurring in solution and colloidal particles, with an absorption energy of about 2.5 eV (20,000 cm^?1). No evidence is found for the presence of very short polymer chains in partially polymerized monomer at low conversion. The relationship of these results to those for deformed single crystals is briefly discussed.     

Micellenbildung in Block-Copolymerisat-L?sungen

Ohne Zusammenfassung     

Saturation of density-charge algebra

It is shown, with rather general assumptions, that the U(6)_W density-charge commutation relations at infinite momentum cannot be saturated with nonexotic states.     

Dunham potential energy coefficients of the hydrogen halides and carbon monoxide

The Dunham potential energy coefficients a_i, 0 ≤ i ≤ 6 (except 4 for HI) have been derived from spectroscopic data of hydrogen halides HF, HCl, HBr, and HI, and carbon monoxide in their ground electronic states. A full error analysis has produced standard deviations of both these a_i and further energy coefficients Y_lj. Comparison with experimental data shows good agreement; trends in the hydrogen halide series are discussed.     

Mixed halide complexes of lead. A comparison with theoretical predictions

Experimentally and theoretically derived formation constants of mixed lead halide complexes are compared at 25.0°C and one molar ionic strength. The formation constant of PbBrCl, ₁₁=79±10, is somewhat larger than the theoretical results, ₁₁=55, predicted using the formation constants of PbBr₂ and PbCl₂. The molar absorptivity of PbBrCl was observed to be intermediate in character between the molar absorptivities of PbBr₂ and PbCl₂. Determinations of the formation constants of PbBr₂Cl^– and PbBrCl₂ ^– are in reasonable agreement with the predictions based on the formation constants of PbBr₃ ^– and PbCl₃ ^–. Mixed ligand species dominated the complexation scheme of Pb(II) in our test media.     

Untersuchungen von verdampfungs- und plasmaprozessen in der graphitrohrküvette zur optimierung von AA-bestimmungen—II. Molekülabsorptions-spektrometrische und atomabsorptions-spektrometrische untersuchungen an wäßrigen Lösungen und organischen extrakten des galliums und indiums

The authors compared the sensitivities achieved in the determination of Ga and In by AAS with electrothermal atomization in graphite cuvettes in dependence on the solvent, i.e. some acids and organic extracts. The best sensitivity was found in an HNO₃ environment. Signal depressions were observed especially in the presence of halides and with solvents containing halogens. The results of the investigations showed that the principal cause of the depressions is the formation of stable molecules of the type MX (M = Ga or In; X = Cl or Br) in the gaseous state. A second cause is the evaporation. The temperature, in particular that prevailing during the ashing step affects the X-concentration in the gaseous state because of thermal hydrolysis of unstable salts or evaporation of the organic solvents.     

Anomalous transmission of swift electrons in thick crystals

A large penetration of swift electrons along the lattice crystallographic axes was observed. The center transmission peak of 2 MeV electrons along the 〈100〉 axis in 110 μm NaCl shows a narrow dip of width at half-minimum (0.2 ± 0.05). The half-width of the maximum base (0.7 ± 0.1) is in agreement with the classical mechanical calculation.