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)2P(O)CH2]2C5H3NO 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)2P(O)CH2]2C5H2NO (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)2P(O)CH2]2C5H3NO. 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.