ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Spectral and Extraction Study of Cd DTC Chelates

D. Oktavec, J. Lehotay, and V. Vrábel

Department of Analytical Chemistry, Faculty of Chemical Technology, Slovak University of Technology, SK-812 37 Bratislava

E-mail: vrabel@cvt.stuba.sk

Abstract: The absorption spectra in the range of λ = 200-350 nm and IR spectra in the range of υ (over tilde) = 200-1700 cm^-1 of cadmium(II) dithiocarbamate chelates are described. The values of the molar absorptivity of the absorption bands of chelates with ligands derived from diethyl-, dipropyl-, diisopropyl-, dibutyl-, diisobutylamine and piperidine around 260 nm and 280 nm were determined in the range 24 900-32 000 dm³ mol^-1 cm^-1 or 13 500-21 400 dm³ mol-1 cm^-1. On the basis of spectral properties there is a dependence of the values of ε and λ_max at about 265 nm (this wavelength is recommended for the spectrophotometric determination of cadmium) on alkyl substituents in the dithiocarbamate ligand. The influence of the solvent polarity on the shift of λ_max, the influence of alkyl substituents in the dithiocarbamate ligands on the values of wavenumber of their normal vibrations, and the influence of the central atom on the intensity of the absorption band at approximately 265 nm and the efficiency of the extraction are discussed. Chloroform extraction curves of Cd(II) chelates under investigation are drawn in the range of pH 1-11. The optimal pH values for determination of Cd(II) in the form of dithiocarbamate complexes and detection limits of Cd spectrometric determination are given.

Full paper in Portable Document Format: 554a233.pdf

Chemical Papers 55 (4) 233–238 (2001)