Collect. Czech. Chem. Commun. 1983, 48, 2009-2014

Extraction of hafnium into benzene with tetraphenyl imidodiphosphate

Oldřich Navrátila, Miroslav Cigáneka and Eckhard Hermannb

a Department of Inorganic Chemistry, Purkyně University, 611 37 Brno
b Section of Chemistry, Technical University, 8027 Dresden, G.D.R.


The distribution of hafnium(IV) was studied between aqueous solutions of perchloric, hydrochloric, or nitric acids (HX) and benzene solutions of tetraphenyl imidodiphosphate (HA). From perchloric and hydrochloric acids at concentrations cHX ⪬ 3 mol l-1 hafnium extracted as HfXA3 complex. With the two acids present at higher concentrations or with nitric acid at concentrations cHNO3 ≥ 1.5 mol l-1 the initial ion exchange mechanism turns into a solvation mechanism associated with the formation of HfX4(HA)y complexes (X = ClO4, Cl). The extraction constant values are given and the extracting agent is compared with other acid organophosphorus reagents.