Abstract The sol-gel synthesis of Nb 2 O 5 was followed by X-ray absorption experiments at the niobium K edge. The molecular precursor NbCl 2 (OEt) 3 was a chloro-alkoxide obtained from the reaction of NbCl 5 with EtOH. Cl ligands were removed upon hydrolysis and condensation, leading to polymeric species formed mainly of corner-sharing NbO 6 octhaedra. Some edge-sharing species were also observed and the short-range order ...