Abstract
Syntheses for new ligands based upon dibenzothiophene and dibenzothiophene sulfone platforms, decorated with phosphine oxide and methylphosphine oxide donor groups, are described. Coordination chem. 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 detns. reveal a range of chelation interactions on Ln(III) ions. The HNO3 dependence of the solvent extn. performance of 9 and 10 in 1,​2-​dichloroethane for Eu(III) and Am(III) is described and compared against the extn. behavior of related dibenzofuran ligands (2, 3; R = Ph) and n-​octyl(phenyl)​-​N,​N-​diisobutylcarbamoylmethyl phosphine oxide (4) measured under identical conditions.
