Sabrina Ouizem

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.

Synthesis and lanthanide coordination chemistry of CMPO-decorated dibenzothiophene and dibenzothiophene sulfone platforms

Abstract Syntheses and spectroscopic characterization data for two new hybrid chelating ligands, 4,6-bis[(diphenyl-N,N-diethylcarbamoylmethylphosphine oxide)methyl]dibenzothiophene (2) and 4,6-bis[(diphenyl-N,N-diethylcarbamoylmethylphosphine oxide)methyl]dibenzothiophene 5,5-dioxide (3), that contain two CMPO fragments grafted onto dibenzothiophene and dibenzothiophene sulfone platforms, respectively, are presented. Coordination chemistry with selected lanthanide nitrates is described along with a X-ray crystal structure determination for an unexpected Eu(III) complex, Eu(4)(NO3)3 that contains the intermediate ligand oxidation species 4,6-bis[(diphenyl-N,N-diethylcarbamoylmethylphosphine oxide)methyl]dibenzothiophene 5-oxide (4).

Synthesis, Ligation and Solvent Extraction Properties of NCMPO-decorated Pyridine and Pyridine N-oxide Platforms

Stepwise syntheses of 2-{[2-(diphenylphosphoryl)acetamido]methyl}pyridine 1-oxide, 2-[Ph2P(O)CH2C(O)N(H)CH2]C5H4NO (6), 2-{[2-(diphenylphosphoryl)acetamido]methyl}-6-[(diphenylphosphoryl)methyl]pyridine 1-oxide, 2-[Ph2P(O)CH2C(O)N(H)CH2]-6-[Ph2P(O)CH2]C5H3NO (7) and 2,6-bis{[2-(diphenylphosphoryl)acetamido]methyl}pyridine 1-oxide, 2,6-[Ph2P(O)CH2C(O)N(H)CH2]2C5H3NO (8), are reported along with spectroscopic characterization data and single crystal X-ray diffraction structure determination for 6·2H2O, 7 and 2,6-[Ph2P(O)CH2C(O)N(H)CH2]2C5H3N·MeOH 18·MeOH, the pyridine precursor of 8. Molecular mechanics computations indicate that 6, 7 and 8 should experience minimal steric hindrance to donor group reorganization that would permit tridentate, tetradentate and pentadentate docking structures for the respective ligands on lanthanide cations. However, crystal structure determination for the lanthanide complexes, {[Yb(6)(NO3)3]·(MeOH)}n, {[Lu(6)(NO3)3]·(MeOH)}n, [Er(6)2(H2O)2](NO3)3·(H2O)4}n, {[La(13)(NO3)3(MeOH)]·(MeOH)}n, {[Eu(7)(NO3)2(EtOAc)0.5(H2O)0.5](NO3)}2·MeOH and [Dy3(7)4(NO3)4(H2O)2](NO3)5·(MeOH)5·(H2O)2 reveal solid-state structures with mixed chelating/bridging ligand : Ln(III) interactions that employ lower than the maximal denticity. The binding of 6 and 7 with Eu(III) in the solid state and in MeOH solutions is also accessed by emission spectroscopy. The acid dependence for solvent extractions with 6 and 7 in 1,2-dichloroethane for Eu(III) and Am(III) in nitric acid solutions is described and compared with the behavior of n-octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (OPhDiBCMPO, 1b) and 2-[(diphenyl)phosphinoylmethyl]pyridine N-oxide (DPhNOPO, 4a).

CCDC 977955: Experimental Crystal Structure Determination

Related Article: Sabrina Ouizem, Sylvie L. Pailloux, Alisha D. Ray, Eileen N. Duesler, Diane A. Dickie, Robert T. Paine, Benjamin P. Hay|2014|Eur.J.Org.Chem.||3132|doi:10.1002/ejoc.201400120

Unexpected Transformation of a Schiff Base Pyridine N-Oxide in the Presence of Pr(NO3)3 · 6H2O

Abstract The synthesis of (E)-((6-(((3-hydroxy-4-methoxybenzylidene)amino)methyl)-N-oxide-pyridin-2-yl)methyl)diphenylphosphine oxide 1 and its unexpected transformation during efforts to study the coordination chemistry with Pr(NO3)3·6H2O are described. GRAPHICAL ABSTRACT