Optical and crystallographic evidence for the choice of space group,nature of the crystal phase change and high birefringence in Ln(Apy)6I3

Reexamination of the structures and electronic spectra of Ln(antipyrene)₆I₃ crystals indicates that the series is isomorphous [space groupR3, (No. 146);Z=1] at room temperature despite spectral evidence of a centric ligand field for the Ln ions. High birefringence and phase changes at lower temperatures (<60 K for Ln=Pr) limit the possibilities for CD meaurement.     

Components of ideals in a commutative ring

Summary The notion of the S-component of an ideal is generalized, and the principal properties of the generalization are given. In memory of Guido Castelnuovo in the recurrence of the first centenary of his birth.     

Raman scattering from 1T-TaS2

Raman measurements on the 1T-polytype of TaS₂ are reported. In the commensurate charge density wave state, a large number of Raman-active peaks are observed below 400 cm^-1. Most of these peaks are attributed to k = 0 optic phonons resulting from superlattice formation.     

Reductive alkylation of beta-alkoxy aziridines: new route to substituted allylic amines

[reaction: see text] A new route to substituted cyclic allylic amines via the reductive alkylation of beta-alkoxy aziridines using excess alkyllithium reagents is described.