Synthesis and Lanthanide Coordination Chemistry of Phosphine Oxide Decorated Dibenzothiophene and Dibenzothiophene Sulfone Platforms

Syntheses
for new ligands based upon dibenzothiophene and dibenzothiophene sulfone
platforms, decorated with phosphine oxide and methylphosphine oxide
donor groups, are described. Coordination chemistry of 4,6-bis­(diphenylphosphinoylmethyl)­dibenzothiophene
(8), 4,6-bis­(diphenylphosphinoylmethyl)­dibenzothiophene-5,5-dioxide
(9) and 4,6-bis­(diphenylphosphinoyl)­dibenzothiophene-5,5-dioxide
(10) with lanthanide nitrates, Ln­(NO3)3·(H2O)n is outlined,
and crystal structure determinations reveal a range of chelation interactions
on Ln­(III) ions. The nitric acid dependence of the solvent extraction
performance of 9 and 10 in 1,2-dichloroethane
for Eu­(III) and Am­(III) is described and compared against the extraction
behavior of related dibenzofuran ligands (2, 3; R = Ph) and n-octyl­(phenyl)-N,N-diisobutylcarbamoylmethyl phosphine oxide (4) measured under identical conditions.