Phosphinoyl Grignard-based substitutions on 2,6-bis(chloromethyl)pyridine followed by N-oxidation of the intermediate 2,6-bis(phosphinoyl)methylpyridine compounds with mCPBA give the target trifunctional ligands 2,6-bis[bis(2- trifluoromethylphenyl)phosphinoylmethyl]pyridine 1-oxide (2a) and 2,6-bis[bis(3,5-bis(trifluoromethyl)phenyl)phosphinoylmethyl] pyridine 1-oxide (2b) in high yields. The ligands have been spectroscopically characterized, the molecular structures confirmed by single crystal X-ray diffraction methods, and the coordination chemistry surveyed with lanthanide nitrates. Single crystal X-ray diffraction analyses are described for the coordination complexes Nd(2a)(NO 3) 3, Nd(2a)(NO 3) 3 · (CH 3CN) 0.5, Eu(2a)(NO 3) 3, and Nd(2b)(NO 3) 3 · (H 2O) 1.25 in each case the ligand binds in a trident-ate mode to the Ln(III) cation. These structures are compared with the structures found for lanthanide coordination complexes of the parent NOPOPO ligand, [Ph 2P(O)CH 2] 2C 5H 3NO.
|Original language||English (US)|
|Number of pages||10|
|State||Published - Apr 17 2009|