Naslov
Extraction of niobium(V) thiocyanate complexes

Autori
Tamhina, Biserka ; Gojmerac Ivšić, Astrid

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
XV. Meeting of Croatian Chemists and Chemical Engineers: abstracts / Gojo, Miroslav ; Trajkov, Nada ; Smolec, Sonja - : Hrvatsko društvo kemijskih inženjera i tehnologa (HDKI), 1997, 217-217

Skup
XV. hrvatski skup kemičara i kemijskih inženjera

Mjesto i datum
Opatija, Hrvatska, 24.03.1997. - 26.03.1997

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
extraction ; niobium(V) complex

Sažetak
The niobium(V) complex formed with thiocyanate in a hydrochloric or a sulphuric acid solution can be extracted with tetraphenylarsonium (TPA) or tetraphenylphos-phonium (TPP) chloride in chloroform as a complex that has a maximum absorbance at 320 and 390 nm. The increased thiocyanate ion concentration intensifies the 390 nm maximum and simultaneously decreases the absorption at 320 nm. The increased chloride ion concentration intensifies the 320 nm absorption, but the absorption spectra retain both maxima. This indicates a possible presence of a series of mixed chloro thio-cyanato niobates(V) in the organic phase. If extraction is carried out from a hydrochloric or a sulphuric acid solution with TPA or TPP chloride in a chloroform-acetone solution (8:2), the extracted complexes have a maximum absorption at 390 nm only. If extraction is carried out from a hydrochloric or a sulphuric acid solution with cetyl- trimethylammonium (CTMA) bromide as a surfactant and as an ion-pair extraction reagent, the extracted complex in chloroform or dichloromethane also has a maximum absorption at 390 nm only.This indicates that the thiocyanato niobate(V) is extracted with TPA or TPP chloride in a chloroform-aceton solutions (8:2) or with CTMA bro-mide in chloroform. The experimental conditions for the quantitative extraction of niobium(V) with the in-vestigated extractants and solvents are described. The compositions of the extracted complexes are also determined and the dependence of complex composition on the extractant and solvent used is discussed.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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