Self-Assembled Monolayer of Cr7Ni Molecular Nanomagnets by Sublimation
Self-Assembled Monolayer of Cr7Ni Molecular Nanomagnets by Sublimation
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DOI：
10.1021/nn201800e
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发表时间：
2011-09-01
期刊：
影响因子：
17.1
通讯作者：
Affronte, Marco
中科院分区：
文献类型：
--
作者：
Ghirri, Alberto;Corradini, Valdis;Affronte, Marco
我们表明，通过互补光谱和STM分析，Cr 7 Ni衍生物是适合在超高真空条件下升华。Cr 7 Ni-bu与金表面的结合较弱，可以在金表面相对自由地扩散，形成二维六方堆积的单层膜。相反，通过向中心二丁胺添加官能硫醇基团，促进分子与表面金吸附原子之间的共价键，导致强分子接枝和无序单层的形成。这两个例子证明了控制一个大的分子复合物的组装的可能性，合理化的DFT计算，建立不同的能量尺度的沉积过程。此外，低温XMCD谱表明，在超高真空中沉积在金上的Cr 7 Ni环的磁性特征相对于相应的块状样品保持不变。
We show, by complementary spectroscopic and STM analysis, that Cr7Ni derivatives are suitable to be sublimed in UHV conditions. Cr7Ni-bu weakly bonds to gold surface and can diffuse relatively freely on it, forming monolayers with hexagonal 2D packing. Conversely, by adding a functional thiol group to the central dibutylamine, a covalent bond between the molecule and surface gold adatoms is promoted, leading to a strong molecular grafting and the formation of a disordered monolayer. These two examples demonstrate the possibility to control the assembly of a large molecular complex, as rationalized by DFT calculations that establish different energy scales in the deposition processes. Moreover, low-temperature XMCD sprectra show that the magnetic features of Cr7Ni rings deposited in UHV on gold remain unchanged with respect to those of the corresponding bulk sample.