Synthesis and coordination chemistry of arene soluble 4-alkyl-2,6-bis[(diphenylphosphino)methyl]pyridine N,P,P′-trioxide ligands

The trifunctional ligand 2,6-[(C6H5)(2) P(O) CH2](2)C5H3NO forms stable complexes with trivalent and tetravalent f-element cations and it acts as an effective liquid-liquid extraction reagent when it is dissolved in CHCl3. In a search for more hydrocarbon solvent soluble extraction reagents, derivative ligands having alkyl substituents in the 4-pyridyl ring position, 4-R'-2,6-[(C6H5)(2) P(O) CH2](2)C5H2NO (R' = Et, Oct), have been prepared and characterized. A single crystal X-ray diffraction analysis for the Et derivative shows that the ligand molecular structure is closely related to the parent ligand, 2,6-[(C6H5)(2)P(O) CH2](2) C5H3NO. The coordination chemistry of the ligands with Nd(NO3)(3) has been examined, and the molecular structures of two complexes obtained with 1 : 1 and 2 : 1 ligand : metal reactant ratios are reported.