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(NO 3 ) 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 [Nd L 3 ] 3+ · 3(NO 3 ) − · MeCN ( 1 ), [Eu L 3 ] 3+ · 3(NO 3 ) − · [Eu(NO 3 ) 3 · 4H 2 O] · MeCN ( 2 ), and [Lu L 3 ] 3+ · 3(NO 3 ) − · [Lu(NO 3 ) 3 · 3H 2 O] · 2 MeCN · 0.5 H 2 O ( 3 ) are reported together with their IR and Raman spectra. All the compounds studied contain isostructural [Ln L 3 ] 3+ cations and three NO 3 − 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.