Encapsulation of single-molecule magnets in carbon nanotubes

Abstract

next-generation electronic, photonic or spintronic devices will be based on nanoscale functional units, such as quantum dots, isolated spin centres or single-molecule magnets. The key challenge is the coupling of the nanoscale units to the macroscopic world, which is essential for read and write purposes. Carbon nanotubes with one macroscopic and two nanoscopic dimensions provide an excellent means to achieve this coupling. Although the dimensions of nanotube internal cavities are suitable for hosting a wide range of different molecules, to our knowledge, no examples of molecular magnets inserted in nanotubes have been reported to date. Here we report the successful encapsulation of single-molecule magnets in carbon nanotubes, yielding a new type of hybrid nanostructure that combines all the key single-molecule magnet properties of the guest molecules with the functional properties of the host nanotube. The findings may pave the way to the construction of spintronic or ultrahigh-density magnetic data storage devices.

Ultra-low temperature structure determination of a Mn12 single-molecule magnet and the interplay between lattice solvent and structural disorder

“…2 K. We have described a more complete model of the disorder and hydrogen-bonding network inherent to the structure by using a combination of ultra-low temperature single-crystal Xray and single-crystal neutron diffraction experiments. We have found an additional hydrogen bond in the disordered region that contributes to a clear understanding of how the lattice solvent transmits disorder to the {Mn 12 (3), prepared from 1 via singlecrystal to single-crystal transformations, we have determined that disorder in the acetic acid of crystallisation is responsible for the positional disorder in an acetate ligand. Upon removal of the acetic acid of crystallisation, the positional disorder in the acetate ligand O6/O7/C3/C4 is largely resolved.…”

“…The interstitial voids are filled with water and acetic acid of crystallisation, both of which take part in hydrogen bonding to the complex. The acetic acid molecules are disordered about a 2-fold rotation axis and lie directly between two adjacent {Mn 12 } clusters. The {Mn 12 } cluster lies on a crystallographic S 4 axis and the eight Mn III Jahn-Teller axes are approximately aligned forming a magnetic easy axis.…”

“…The acetic acid molecules are disordered about a 2-fold rotation axis and lie directly between two adjacent {Mn 12 } clusters. The {Mn 12 } cluster lies on a crystallographic S 4 axis and the eight Mn III Jahn-Teller axes are approximately aligned forming a magnetic easy axis. 16 Scans of dc magnetisation vs. field show sharp steps in hysteresis loops at well-defined field strengths.…”

“…8 SMMs are of particular interest because of their potential for storing and processing information at the molecular level. 9,10 Recent work has focused strongly on integrating SMMs on surfaces and devices, 11 including carbon nanotubes, 12 with the aim of achieving a workable coupling between the nanoscale units and the macroscopic world. 1 possesses an S=10 ground state and a significant axial anisotropy, D ≈ -0.5 cm -1 .…”

“…Elemental analysis is consistent with the majority of crystals being species 2, with a small amount of 3 present. Thus, we cannot claim to have produced pure samples of axially symmetric {Mn 12 acetate} complexes. However we have shown that full removal of the acetic acid of crystallisation resolves the disorder in the O atoms of the acetate ligands, producing species that have true, unbroken S 4 symmetry.…”