Abstract
Phosphinoyl Grignard-based substitutions on 2,6-bis(chloromethyl)pyridine followed by N-oxidation of the intermediate 2,6-bis(phosphinoyl)methyl pyridine compounds with mCPBA give the target trifunctional ligands 2,6-bis[bis-(2-trifluoromethyl-phenyl)-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)(NO3)3, Nd(2a)(NO3)3���(CH3CN)0.5, Eu(2a)(NO3)3 and Nd(2b)(NO3)3���(H2O)1.25; in each case the ligand binds in a tridentate mode to the Ln(III) cation. These structures are compared with the structures found for lanthanide coordination complexes of the parent NOPOPO ligand, [Ph2P(O)CH2]2C5H3NO.