Surprising Coordination Geometry Differences in Ce^IV‐ and Pu^IV‐Maltol Complexes

Abstract

Abstract As part of a study to characterize the detailed coordination behavior of Pu IV , single‐crystal X‐ray diffraction structures have been determined for Pu IV and Ce IV complexes with the naturally occurring ligand maltol (3‐hydroxy‐2‐methylpyran‐4‐one) and its derivative bromomaltol (5‐bromo‐3‐hydroxy‐2‐methylpyran‐4‐one). Although Ce IV is generally accepted as a structural analog for Pu IV , and the maltol complexes of these two metals are isostructural, the corresponding bromomaltol complexes are strikingly different with respect to ligand orientation about the metal ion: All complexes exhibit trigonal dodecahedral coordination geometry but the Ce IV –bromomaltol complex displays an uncommon ligand arrangement not found in the Pu IV complex.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)