Photolysis of Methyltrioctylammonium Tetrachloroferrate(III)

Abstract

It has been revealed that iron(III) complex containing methyltrioctylammonium chloride(MTOAC;RR₃'NCl, R=CH_3-, R'=C₈H_17-), RR₃'N[FeCl₄], was decomposed by light. On this study, the authors explore the photolysis of MTOAC-Fe(III) complex, MTOA[FeCl₄] during the extraction procedure from iron(III) hydrochloric acid solution with extractants in benzene. It was deduced that dihexyl sulfide(DHS;R₂''S, R''=C₆H_3-) accelerated the photolysis, and that the photolysis was suppressed with the increase of MTOAC concentration. The effect of oxygen during the above procedure and the electronic spectra in aqueous phase suggest that complex MTOA[FeCl₄] was reduced to iron(II) species through decomposition and was then gradually re-oxidized to iron(III) by air upon standing. Triisobutylphosphine sulfide(Cyanex 471X; R₃'''PS, R'''=i-C₄H_9-), which is the neutral sulfur-containing extractant, also showed the same behavior with DHS for the photolysis of the complex. The photolysis mechanism was discussed based on these results.