Two-leg molecular ladders formed by hierarchical self-assembly of an organic radical.
The supramolecular organization of a new polychlorotriphenyl (PTM) radical bearing three long alkyl chains has been studied by scanning tunneling microscopy (STM) at the liquid-solid interface. This radical hierarchically self-assembles on graphite forming head-to-head dimers that organize in rows following an interesting spin-containing two-leg molecular ladder topology, in which the alkyl chains determine the space between the radical rows and act as diamagnetic barriers. In addition, these double-rows also self-assemble three-dimensionally, leading to a multilayer organization which is still influenced by the HOPG substrate symmetry. The observed nanostructures are sustained by different intermolecular interactions such as Cl...Cl, Cl...Ph, pi-pi, van der Waals, and CH...pi interactions. Theoretical calculations were used to model the observed assemblies, and the results were in complete agreement with the experimental data. Remarkably, atomic force microscopy (AFM) studies confirmed that this tendency to form double rows composed by the PTM magnetic heads surrounded by the alkyl chains is maintained after the complete evaporation of the solvent. The electrochemical and magnetic properties of these PTM nanostructures were also demonstrated.
Institut de Ciencia de Materials de Barcelona (ICMAB-CSIC), Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Bellaterra, Spain.
Núria
N
Crivillers
Shuhei
S
Furukawa
Andrea
A
Minoia
An
A
Ver Heyen
Marta
M
Mas-Torrent
Christian
C
Sporer
Mathieu
M
Linares
Alexander
A
Volodin
Chris
C
Van Haesendonck
Mark
M
Van der Auweraer
Roberto
R
Lazzaroni
Steven
S
De Feyter
Jaume
J
Veciana
Concepció
C
Rovira
D004563:Electrochemistry; D005609:Free Radicals / Q000138:chemical synthesis / Q000737:chemistry; D046911:Macromolecular Substances / Q000138:chemical synthesis / Q000737:chemistry; D008280:Magnetics; D018625:Microscopy, Atomic Force; D016252:Microscopy, Scanning Tunneling; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry; D010316:Particle Size; D011080:Polychloroterphenyl Compounds / Q000138:chemical synthesis / Q000737:chemistry*
D005609:Free Radicals; D046911:Macromolecular Substances; D011080:Polychloroterphenyl Compounds