Résumé
The new methacrylate-substituted manganese carboxylate cluster [Mn
12
O
12
{CH
2
C(CH
3
)COO}
16
(H
2
O)
4
] having single molecule magnetic (SMM) properties was synthesized and fully characterized by X-ray crystallography, LDI-TOF, fast atom bombardment (FAB) analyses and magnetic measurements. This cluster, containing sixteen polymerizable functionalities, was used as a cross-linker in the radical copolymerization with methyl methacrylate monomer in order to obtain hybrid cross-linked copolymers. The obtained nanocomposites were studied by infrared spectroscopy, magnetic measurements, thermogravimetric analysis, differential scanning calorimetry and transmission electronic microscopy. All these methods, along with the study of the swelling properties, reveal that the intact manganese cluster is enwrapped and covalently bonded to the polymer matrix, allowing to improve its chemical and thermal stability. The resulting nanocomposite materials have SMM properties.
The magnetic properties of individual manganese carboxylate clusters, copolymerized with MMA, are transferred to the hybrid material, while the polymeric matrix protects the clusters, thus improving their chemical and thermal stability.