59Co nuclear magnetic resonance in antiferromagnetic CsCoCl3

The ⁵⁹Co NMR in a CsCoCl₃ single crystal has been observed by the spin echo method at 4.2 K. The obtained spectrum is composed of seven distinct lines split by the nuclear-quadrupole interaction. The frequency of the central (± $\text{1}\text{2}$ ? ± $\text{1}\text{2}$) transition 502.08±0.05 MHz corresponds to the hyperfine field of 499.38 ± 0.05 kOe, which agrees well with the calculated value. Due to the interaction of the nucleus with the electronic moment induced by the external field, a shift as large as 18% was observed for the nuclear g-factor.     

Spin-dependent momentum distribution in iron

Spin-dependent Compton profiles and positron annihilation angular distributions were calculated by the APW method for ferromagnetic iron and compared with the corresponding experiments. Good agreement obtained between theory and experiment on positron annihilation may support the calculated band structure over the complete extent of the occupied bands, especially the results obtained by the present theory for the s-d hybridization occurring in the d-bands.     

Syntheses of “thiiranoradialenes”

A stable tetramethylthiiranoradialene, 2,3-diisopropylidenethiirane $\text{6}$, was prepared by pyrolysis of lithium salt of tosyl hydrazone of 2,2-dimethyl-4-isopropylidene-3-thietanone. The corrsponding sulfoxide $\text{7}$ was also prepared by oxidation of $\text{6}$.     

The radiative photino decay into a higgsino

The radiative decay of the photino (γ&#x0304;) to a higgsino (H?) is calculated in the minimal supersymmetric electroweak theory coupled to N = 1 supergravity. From the recent analyses on two photon production at PETRA, we find that the possibility that $\text{m}{}_{\mathrm{<mtext>H</mtext><mtext>?</mtext>}}\text{/m}{}_{\mathrm{<mtext>\gamma </mtext><mtext>?</mtext>}}\text{<1}$ is almost excluded, unless $\text{m}{}_{\mathrm{<mtext>\gamma </mtext><mtext>?</mtext>}}\text{?}\text{O}\text{(20)}\text{GeV}$. We also calculated the cross section for $\text{e}{}^{\mathrm{+}}\text{e}{}^{\mathrm{-}}\text{→}\text{γ}\text{?}\text{→γ}\text{H}\text{?}\text{+γ}\text{H}\text{?}$ as a function of photon energy.     

A new strategy to sulfur heterocycles: Reactions of an allene episulfide with electrophiles

A variety of sulfur-containing five- and six-membered cyclic compounds was obtained by the acid-catalyzed and thermal reactions of an allene episulfide with various electrophiles.     

The relationship between chemical structure and viscoelastic properties of linear aliphatic polyesters

The effects of Chemical structure on the molecular motions in linear aliphatic polyesters have been investigated with a free-oscillation torsion pendulum. Broad-line NMR provided supplementary information. In the γ relaxation which corresponds to the local-mode motions of main chains in the noncrystalline region, the polyesters which are composed of two methylene units in the diol part of the chemical repeat unit showed an extremely asymmetric loss curve with a relatively high-loss peak temperature compared with that of the other polyesters. In addition to the two relaxations (β,γ) which have been observed in earlier dielectric measurements, a new relaxation (α) was found on the high-temperature side of the glass transition of the polyesters. The α relaxation was assigned to molecular motions of methylene segments in the crystalline region. The α and β relaxations of the two-dimensional series are situated close to the temperatures found for other polyesters with rather long methylene sequence in the chemical repeat unit. The results were explained in terms of a difference on the chain mobility in the noncrystalline regions which may be related to the difference of chemical structure of the polyesters.