THE EFFECTS OF OPTICALLY INACTIVE IONS ON THE ROTATORY DISPERSION OF ASYMMETRIC COMPLEX IONS

Abstract

Considerable interest in the optical rotatory dispersion of asymmetric organic and inorganic compounds and its application to the elucidation of their structures has arisen in recent years. In order to study the effects of optically inactive ions on the rotatory dispersion of asymmetric complex ions, a series of salts was prepared of two active cations: levo cis-oxalato-bis(ethylenediamine)cobalt(III) and levo tris(ethylenediamine)chromium(III). Salts prepared included the fluoride, chloride, bromide, iodide, tetrafluoroborate, perchlorate, sulphate, and phosphate. In order to study this effect on an optically active anion, the lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, and barium salts of dextro and levo tris(oxalato)rhodate(III) were also prepared. Rotatory dispersion curves and absorption spectra were obtained for all salts in water solution. A comparison of the curves within a series showed definite trends in changes of wavelength and intensity of maxima of rotation and absorption with changes in both the ionic charge/size ratio (ionic potential) and polarizability of the optically inactive ions.