A series of gold nanoparticles functionalized with TEMPO-modified disulfide 2 have been prepared and studied by electron paramagnetic resonance (EPR) spectroscopy, UV-vis, transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), and thermogravimetric analysis (TGA). In order to increase the packing of spin labels on the particle surface, heat-induced size evolution and ligand exchange reactions were used. The optimized synthesis included a one-pot reaction at room temperature that led to gold nanoparticles with a controlled large size (ca. 7 nm) and high coverage of radicals. These nanoparticles showed a |Δms| = 2 transition at half-field, which gives direct evidence of the presence of a high-spin state and permits an EPR study of the nature of the magnetic coupling between the spins. The results showed dominant antiferromagnetic interactions between radicals, but at lower temperatures, a ferromagnetic contribution was observed.
|Titolo:||Magnetic interactions in Spin-labeled Au nanoparticles|
|Data di pubblicazione:||2014|
|Appare nelle tipologie:||2.1 Articolo su rivista |
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|Journal of Physical Chem2014.pdf||full text||Versione dell'editore||Accesso chiuso-personale||Riservato|