Two photon magnetooptic effects

The theory of two photon magnetooptic effects such as polarization rotation and circular dichroism is developed. An effect which has not been previously discussed, the optical analog of the Hanle effect, is proposed.     

Photochemically induced electron transfer from [3]ferrocenophanylbutanoate anions

The anions of 4-([3]ferrocenophanyl)butanoic acids (Id and IId), when excited by light of around 240 nm wavelength in aqueous solution in the presence of N₂O, undergo photo-oxidation to zwitterions (III and IV respectively) in a manner completely analogous to the reaction of 4-ferrocenylbutanoate anion. The differences in the kinetic parameters of the reactions are thought to be attributable in part to slight tilting of the cyclopentadienyl rings caused by the connecting trimethylene bridge.     

1,4-cycloaddition of nitrosobenzene to N-ethoxycarbonylazepine

A new stable product from the reaction of nitrosobenzene and N-ethoxycarbonylazepine is shown to be a 1,4-cycloadduct.     

Simplified analysis of gas/polymer selective solubility behavior

Interactions of penetrants with gas separation membrane materials can have both desirable and undesirable consequences. Improved permselectivity resulting from specific polymer/penetrant interactions must be balanced against potentially undesirable plasticization effects resulting from such interactions. Consideration is given to the utility of gas solubility measurements in low-molecular-weight solvents as an aid to understanding solubility data for polymer/gas systems. The solubility coefficients of gases in low-molecular-weight liquids and in polymeric media of similar chemical structure tend to be quite different in magnitude. “Equation-of-state” and combinatorial entropy differences for the free energy of mixing of gases with low-molecular-weight solvents and high-molecular-weight polymers presumably cause this discrepancy. The above complications are minimized and useful trends identified by considering the so-called solubility selectivity comprised of ratios of absolute gas solubilities in both low-and high-molecular-weight media of similar chemical natures. For example, both acetone and methyl acetate are highly sorptive of CO₂ and display a high degree of solubility selectivity for CO₂ relative to CH₄. These two solvents have mass densities of carbonyl groups that are similar to that in cellulose acetate and poly(methyl methacrylate). Both of these polymers are also highly sorptive of CO₂ and have solubility selectivities for CO₂ relative to CH₄ that are similar to that of acetone and methyl acetate. Anomalous behavior is encountered in the case of Kapton poly(ether diimide), which contains a high density of carbonyl groups (four per repeat unit). On the basis of the behavior of the other carbonyl-rich polymers, it was expected that Kapton would show high solubility selectivity for CO₂ relative to CH₄, but this was not observed. A hypothetical explanation for the Kapton behavior is presented. In addition, possible advantages of the Kapton-type behavior are discussed in the context of the reported good plasticization resistance of polyimides.     

Eigenfunctions on symmetric spaces with distribution-valued boundary forms

A characterization is given for those eigenfunctions of invariant differential operators on symmetric spaces of noncompact type which are representable as generalized Poisson integrals of distributions on the boundary, the criterion being that the function grow no faster than some power of the exponential of the distance from the origin. For symmetric spaces of arbitrary rank, the result is proved in one direction only, namely, that the Poisson integral of a distribution satisfies the growth condition; however, for rank one symmetric spaces, the converse is also shown to be true.     

A practical paramagnetic relaxation reagent for aqueous solutions

While there is a useable paramagnetic relaxation reagent (PARR) for use in nonpolar or low polarity solvents, there has not been a practical PARR for use in highly polar solvents. A reagent, Gd(NO₃)₃-inositol, is described which appears to satisfy this need. The performance of the reagent is given in terms of its effect on the T₁, NOE and line width values of N,N-dimethylformamide. In addition, the application of this reagent to adenosine is also reported.     

Divergence of the Bethe-Salpeter wave function at the origin

We point out an error in the proof of Nishijima et al. that the Bethe-Salpeter wave function for composite particles, lying on Regge trajectories, is finite. We describe a simple counter-example drawn from non-relativistic quantum mechanics and cite others from field theory.