Self-assembled monolayers of electroactive polychlorotriphenylmethyl radicals on Au(111).
Two new polychlorotriphenylmethyl (PTM) derivatives bearing a thioacetate and a disulfide group have been synthesized to anchor on gold substrate. On the basis of these molecules, three strategies were followed to prepare self-assembled monolayers (SAMs) of electroactive PTMs. The resulting SAMs were fully characterized by contact angle, atomic force microscopy (AFM), and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). The high coverage surface and stability of the SAMs were demonstrated by cyclic voltammetry. In addition, the electrochemical experiments proved that these SAMs are bistable since it is possible to reversibly switch between the PTM radical state to the corresponding anion. The magnetic response was investigated by electron paramagnetic resonance. We observed that when the PTM SAMs are in their radical form they confer magnetic functionality to the surface, whereas when they are in the anionic state, the surface is diamagnetic. Thus, the PTM-modified substrates are multifunctional surfaces since they combine magnetic and electroactive properties. The reported results show the high potential of these materials for the fabrication of surface molecular devices.
Crivillers
Núria
N
Institut de Ciència de Materials de Barcelona and Networking Research Center on Bioengineering, Biomaterials and Nanomedicine, Campus Universitari de Bellaterra, 08193 Cerdanyola del Vallès, Spain.
Mas-Torrent
Marta
M
Vidal-Gancedo
José
J
Veciana
Jaume
J
Rovira
Concepció
C
D000085:Acetates / Q000737:chemistry; D001665:Binding Sites; D001672:Biocompatible Materials / Q000138:chemical synthesis*; D004563:Electrochemistry; D005609:Free Radicals / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D008280:Magnetics; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D011080:Polychloroterphenyl Compounds / Q000138:chemical synthesis*; D018629:Spectrometry, Mass, Secondary Ion; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013499:Surface Properties
D000085:Acetates; D001672:Biocompatible Materials; D005609:Free Radicals; D011080:Polychloroterphenyl Compounds; D013438:Sulfhydryl Compounds; D006046:Gold