Self-assembled monolayer of Cr7Ni molecular nanomagnets by sublimation.

Ghirri, Alberto; Corradini, Valdis; Bellini, Valerio; Biagi, Roberto; del Pennino, Umberto; De Renzi, Valentina; Cezar, Julio C; Muryn, Christopher A et al. · ACS Nano · 2011

basic_science · Level V

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Abstract

We show, by complementary spectroscopic and STM analysis, that Cr(7)Ni derivatives are suitable to be sublimed in UHV conditions. Cr(7)Ni-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 Cr(7)Ni rings deposited in UHV on gold remain unchanged with respect to those of the corresponding bulk sample.