Lanthanide(III) complexes with phosphoryl containing 1,8-naphthyridine: Crystal structures and vibrational spectra

The complexes of 2-[2-(diphenylphosphoryl)prop-2-yl]-1,8-naphthyridine (L) with lanthanide nitrates Ln(NO3)3 (Ln = Nd, Eu, Lu) were investigated to elucidate the coordination ability of a novel type of potentially tridentate ligands – phosphorylalkyl substituted naphthyridines. The X-ray crystal structures of [NdL3]3+ · 3(NO3)− · MeCN (1), [EuL3]3+ · 3(NO3)− · [Eu(NO3)3 · 4H2O] · MeCN (2), and [LuL3]3+ · 3(NO3)− · [Lu(NO3)3 · 3H2O] · 2 MeCN · 0.5 H2O (3) are reported together with their IR and Raman spectra. All the compounds studied contain isostructural [LnL3]3+ cations and three NO3− counterions. Coordination of each L appears to be O,N,N tridentate-cyclic and coordination number of Ln is nine. Vibrational spectra of 1–3 are also compared with that of free ligand and model compounds.