Synthesis and properties of new (Phosphinoylmethyl)pyridine N-oxides

Sylvie L. Pailloux, Daniel Rosario-Amorin, Manab Chakravarty, Jean Michel Camus, Karen Ann Smith, Eileen N. Duesler, Diane A. Dickie, Robert T. Paine, Kevin K. Klausmeyer, Daniel A. Padron, Benjamin P. Hay, Laetitia H. Delmau

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8 Scopus citations


Syntheses for 2-[1-(diarylphosphinoyl)-1-(pyridin-2-yl)methyl]pyridines, (8a, b), and 2-[1-(diarylphosphinoyl)-1, 1-bis(methylpyridin-2yl)methyl] pyridines, (11a, b), (Ar = C6H5 and 2-CF3C 6H4), based on substitution of 2-methylpyridine fragments onto the exo methylene carbon atom of 2-[(diaryl)phosphinoylmethyl]pyridine platforms, are described. N-oxidations of 8a, b and 11a, b produced the 2-[1-(diarylphosphinoyl)-1-(1-oxy-pyridin-2yl)methyl]pyridine N-oxides (5a, b) and the 2-[1-(diarylphosphinoyl)-1, 1-bis(1-oxy-methylpyridin-2-yl)methyl] pyridines (6a, b), respectively. The "short-arm" pyridine fragment of 11a, b resists N-oxidation, and the fully oxidized molecules, 2-[1-(diarylphosphinoyl)-1, 1-bis(1-oxy-methylpyridin-2-yl)methyl]pyridine N-oxides (7a, b) were not isolated. Molecular mechanics calculations for gas phase 1:1 ligand/lanthanide complexes indicated that 5a should accommodate a tridentate NO(meNO)PO coordination mode with minimal steric strain. In contrast, 7a cannot form tetradentate NO(meNO)2PO chelates; however, tridentate binding should be accessible with minimal ligand strain. Coordination complexes of 8a, b, 5a, b, 6a, b and 11a, b with Ln(NO3)3 salts were isolated and a X-ray crystal structure for [Er(8a)(NO 3)3(MeOH)2]·CH2Cl 2, revealed a monodentate Er-O=P interaction. On the other hand, complexes formed by a more symmetrical trifunctional phenylphosphino-bis-2- methylpyridine N, N, P-trioxide ligand, (meNO)2PO*, {La[(meNO)2PO*)](OTf)2(MeOH)3(H 2O)+}(OTf-) and {Pr[(meNO)2PO* )](OTf)(MeOH)4+}(OTf-)2, realized a tridentate coordination mode. Solvent extraction behaviors for EuIII and AmIII in nitric acid solutions using 5a, b, 6a, b, Ph 3PO and the parent bifunctional ligand 2-[(diphenylphosphanyl)methyl] pyridine N, P-dioxide (3a) in 1, 2-dichloroethane were assessed, and 5a, b and 6a, b were found to behave more like Ph3PO than 3a.

Original languageEnglish (US)
Pages (from-to)1101-1116
Number of pages16
JournalZeitschrift fur Anorganische und Allgemeine Chemie
Issue number7
StatePublished - Jun 2013


  • Actinides
  • Coordination chemistry
  • Lanthanides
  • Phosphine oxides
  • Pyridine N-oxides
  • Solvent extraction
  • X-ray diffraction


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