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The present work is devoted to the magnetic behaviour of Mn12-stearate single-molecule magnets ( [ Mn 12 O 12 ( CH 3 ( CH 2 ) 16 CO 2 ) 11 ( CH 3 CO 2 ) 5 ( H 2 O ) 4 ] · 2 CH 3 COOH ) immobilized inside the SBA-15 mesoporous silica. The stearate’s complexed Mn12, in contrast to the commonly used Mn12-acetate, is soluble in most organic solvents and resistant against water catalyzed reduction. Thus, the precise functionalization of SBA-15 silica by these molecules is possible with no use of sophisticated laboratory equipment. The modified silica matrix in this case provides controlled separation of magnetic molecules, by the use of anchoring units placed inside pores. In order to check the properties of Mn12-stearate molecules regularly distributed inside silica matrix, and check their interactions, samples containing three different concentration of Mn12-stearate molecules were prepared and compared with the bulk Mn12-stearate. All materials have been examined by means of infrared spectroscopy, transmission electron microscopy, X-ray diffraction and squid magnetometry. The obtained results confirmed the successful immobilization of magnetic molecules inside the silica matrices. Moreover, the results of magnetic tests showed a correlation between the amount of magnetic molecules placed inside the mesopores and the magnetic properties of the obtained hybrid materials. |
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