Rotational isomerism in ethylhalogenoarsines

Abstract

I.r. and Raman spectra of EtAsCl₂, EtAsBr₂, Et₂AsCl, and Et₂AsBr have been measured as liquids at room temperature, as cooled liquid films, and as solids. Room temperature data for PhEtAsCl are also reported. Possible rotational isomers are discussed and changes in band intensities with temperature in regions associated with As–C stretching, C–C stretching, and CH₂ deformation modes are interpreted in terms of changes in isomer ratios. ¹H N.m.r. measurements at room temperature give no evidence for the presence of isomers.