Résumé
The Ni-11 square(HPO3)(8)(OH)(6) phosphite was prepared using a hydrothermal method. Depending on the pressure used during the synthesis, different hierarchical superstructures were encountered, including a new original cross-shaped star. The as-obtained products were characterized by X-ray diffraction, scanning and transmission electron microscopy and magnetization. In agreement with the presence of transition metal dimers in the structure, a complex magnetic behavior is observed at low temperature. This magnetic ground-state, combined with the non-centrosymmetry of the space group, creates new opportunities for applications in this class of open framework inorganic materials. (C) 2014 Elsevier Masson SAS. All rights reserved.