Spectroscopic and structural characterization of pureand FeCl3-containing tri-n-butyl phosphate

The spectroscopic properties and liquid structure ofpure tri-n-butyl phosphate (TBP) and FeCl3/TBP solutionshave been investigated by Uv–Vis and Raman spectroscopies,X-ray diffraction and conductometry. Uv–Vis and Ramanspectra, supported by conductometric measurements, consistentlyindicate that the solubilized salt is present mostly asTBPn[FeCl3−n]n+ and FeCl4− complex ions due to specificinteraction with the TBP phosphate group. Thanks to thisinteraction, a high amount of salt (up to 13 % w/w) can bedissolved despite the relatively low dielectric constant of TBP.The X-ray diffractogram of pure TBP has been interpreted interms of three main contributions which can be attributed tospatial pair correlations between atoms of interacting TBPmolecules. In the presence of increasing FeCl3 amounts, ithas been observed a progressive structuring effect, exerted bythe dissolved salt, on the layers of opportunely oriented TBPmolecules due to the formation of the complex ionic species.By simple treatment with NaBH4, the synthesis of Fe nanoparticleshas been achieved. The absence of water, the easinessof preparation, the high amount of salt which can be suspendedand the peculiar physico-chemical properties of such systemsare all elements worth of note for the fields of nanoparticlesynthesis and for specialized technological applications.