Inclusion complex formation in a particular geometry by a water-soluble paracyclophane in aqueous solution — NMR Studies —

NMR studies (¹H and ¹³C) demonstrating an inclusion complex formation in a particular geometry between a water-soluble paracyclophane, CP44, and hydrophobic substrates in acidic aqueous solution are described.     

Stepwise conversion of oxiranes to allylic alcohols by iodotrimethylsilane and DBU

Iodotrimethylsilane, prepared from hexamethyldisilane and iodine reacts smoothly with oxiranes to give (2-iodoalkoxy)trimethylsilanes which can be converted to allylic alcohols with DBU in good yields. The whole conversion can be carried out in one-pot operation.     

Extraction—spectrophotometric determination of palladium with n-butylxanthate

Palladium (6–180 nmol) is extracted quantitatively with potassium n-butyl-xanthate into benzene from an aqueous phase containing EDTA, and determined spectrophotometrically at 290 nm. The molar absorptivity of the complex is 7.5 × 10⁴ dm³ mol^-1 cm^-1.     

Dielectric relaxation in concentrated solutions of poly(γ-benzyl-L-glutamate)

Measurements of dielectric constant and loss, broad-line nuclear magnetic resonance, and differential thermal analysis of concentrated solutions of poly(γ-benzyl-L -glutamate) (PBLG) were carried out to determine the effects of intermolecular interactions on the mobility of the side group and the solvent (dichloromethane or dioxane). Only one dielectric loss peak due to the cooperative motion of the side group and the solvent was found. The activation energy of this relaxation process varied from 3 to 47 kcal/mole with increasing concentration of PBLG from 20 to 100% by weight accompanied with steep increases at about 40 and 80%. This result is explained as due to entanglement of neighboring side groups. In NMR, narrowing of the line was observed near the temperature where the dielectric loss was observed. The glass transition was also observed by differential thermal analysis. From these results it was concluded that the relaxation observed in PBLG solution and in pure PBLG have the nature of primary or α relaxations.     

On the algebraic structure of self-dual gauge fields and sigma models

An extensive and detailed analysis of self-dual gauge fields, in particular with axial symmetry, is presented, culminating in a purely algebraic procedure to generate solutions. The method which is particularly suited for the construction of multimonopole solutions for a theory with arbitrary G, is also applicable to a wide class of non-linear sigma models.The relevant symmetries as well as the associated linear problems which underly the exact solubility of the problem, are constructed and discussed in detail.     

Extraction—spectrophotometric determination of manganese(II) with xanthates

Manganese(II) (0.04–2 μmol) is extracted into chloroform from an aqueous phase at pH 6.5–9.0, containing a large excess of (n-butyl) xanthate and measured spectrophotometrically at 457 nm. The apparent molar absorptivity is 5.5 × 10³ dm³ mol^-1 cm^-1. The extractability of the manganese complexes decreases in the order n-butyl = benzyl- ? n-propyl- ? ethyl- ? methyl-xanthate. Interfering ions can be removed by a preliminary extraction with ethylxanthate. Ni, Co, Zn, Cd, Pb, Hg(II), Fe(III), As(III), Ce(III), Se(IV), V(V), Mo(VI), and the alkali and alkaline earth metals do not interfere.     

Analysis of heat capacity of platinum: Electron-phonon effects and anharmonic contribution

The heat capacity results for platinum from 80 to 1000 K, reported in our previous paper, have been analyzed. The contributions of bare electrons and harmonic phonons to the heat capacity have been evaluated from the available data on the band structure and the phonon spectrum of platinum. At low temperatures, the present estimates for the temperature dependence of the electron-phonon enhancement agree qualitatively with those derived from theoretical calculations found in the literature. The anharmonic heat capacity obtained is negative and linear with temperature in the vicinity of the Debye temperature (237 K), and becomes constant above 450 K. The enhancement in the heat capacity above 1000 K has been analyzed and found to be due mainly to the enlargement of the dilation term corresponding to the similar enhancement in the thermal expansion.