Three amino(polyphenolic) ligands,
N,
N′-bis(5-
tert-butyl-2-hydroxybenzyl)-1,2-diaminoethane
1, tris(5-
tert-butyl-2-hydroxy-3-methylbenzyl)amine
3, its 3-chloro analogue
4 and their Zr
IV complexes have been synthesised. The crystal structure of the Zr
IV complex of tris(5-
tert-butyl-3-chloro-2-hydroxybenzyl)amine, shows this to be [Zr(
4-2H)
2] in which both ligands exists in a zwitterionic form with one alkylammonium and three phenolate groups. The complexes are stable in a two phase, chloroform/water, system at high pH, but the zirconium is stripped at pH < 2.5. The pH value needed to strip 50 % of the Zr
IV from the complex [Zr(
1-4H)] of the tetraphenolic ligand is
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2.0 whilst the complexes [Zr(
3-2H)
2] and [Zr(
4-2H)
2] of the triphenolic ligands are slightly more stable with pH
1/2 values of
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1.4. We were unable to use the ligands to extract zirconium from low pH aqueous zirconium oxychloride solutions into an organic phase under a variety of conditions.