A new polyaminocarboxylate ligand derived from N, C-pyrazolylpyridine was synthesized. The luminescence and relaxometry properties of its Tb3+ and Gd3+ chelates were investigated in aqueous solutions. The Tb3+ chelate is strongly luminescent having remarkable lifetime and quantum yield (τ= 1.82 ms and Φ= 0.42). The 1/T1 proton relaxivity at 20MHz and 25° C (5.3 s− 1mM− 1) of the Gd3+ chelate was found to be comparable to ...