A series of mononuclear complexes based on lanthanide ions has been synthesized and X- ray characterized. The compounds [LnIIIL2 (NO3) 3 (H2O) 2](Ln= La, Ce, Pr, Nd, Sm, Gd and Tm; L= 2, 6-bis (2-formylphenoxymethyl) pyridine) are found to be isomorphous and isostructural. Ligand L systematically coordinates through one carbonyl functionality, and the resulting complexes are placed on a twofold axis in crystals belonging to C2/c space- ...