Spectral Investigation on Ruthenium(III)-allyl Thiourea System

Abstract

Ruthenium(III) forms a 1:2 complex with allyl thiourea. Conformity to Beer's law was observed for up to 12 pg/ml of ruthenium, in acidic medium. The molar absorptivity of the complex is 1.66E+04 1 mol⁻¹ cm⁻¹, at 270 nm; the Sandell's sensitivity of the reaction for ruthenium is 0.0061 μg cm⁻² per 0.001 absorbance unit. The tolerance to diverse ions is quite satisfactory. The infrared spectra of allyl thiourea and of its ruthenium complex, recorded in the 2.5 - 50 μ region, reveal that only sulphur-to-ruthenium bonds are present in the complex. A comparison with the main, most recent, spectrophotometric reagents for ruthenium is reported. The present method has the advantages of simplicity and reasonable sensitivity.