Incorporation of a high-spin heptanuclear [CuII6Gd] cluster into carboxyl-functionalized mesoporous silica

Abstract

We report the immobilization of heptanuclear [Cu₆Gd] high-spin magnetic clusters, namely [Cu₆Gd(aib)₆(OAc)₃(NO₃)₃(OH)₃] (where, aib = (CH₃)₂C(NH₂)COO⁻ and OAc = CH₃COO⁻), inside the channels of –COOH-functionalized mesoporous SBA-15 silica. X-ray diffraction, TEM and N₂ physisorption experiments show that the well-ordered hexagonal structure of the CA/SBA-15 hybrid material is well preserved and that the [Cu₆Gd] clusters are located inside the mesopores. The molecular structure of the incorporated [Cu₆Gd] was confirmed by elemental X-ray microanalysis, IR and UV-vis-NIR spectroscopy. Magnetic measurements indicate that the polynuclear complexes retain their magnetic properties during the impregnation process. The host–guest nanocomposite displays strong ferromagnetic interactions that result in a high-spin S = 13/2 ground state.