Get closer to the intrinsic properties of Ni 2+ salen polymer semiconductors accessed by chain isolation inside silica nanochannels
Résumé
The scientific problem aimed to be solved by our research consists in the charge transport improvement of Ni 2+ salen polymer semiconductors by isolation of individual chains inside mesoporous silica channels capable of ensuring suppression of interchain interactions causing the charge carriers trapping in the continuous polymer films. Elimination of charge trapping is the primary motivation for energy transport improvement in polymer semiconductors serving as interconnections in molecular electronics. With that respect, we prepared molecular wires based on structurally privileged ortho substituted Ni 2+ salen, offering the molecular structure facilitating its linear electropolymerization growth inside the confined space of silica matrix containing 2 nm in diameter vertical channels. We noticed that analogical embedment of ortho unsubstituted poly(Ni 2+ salen)s was not possible. Thus, we engaged quantum chemical calculations utilizing the density functional theory to explain this phenomenon. Hence, we succeeded in recognizing structureproperty relationships of Ni 2+ salens governing their local electropolymerization ability inside vertical nanochannels. Isolation of polymer chains allowed us to get insight into the intrinsic properties of Ni 2+ salen polymers creating a better understanding of their charge transport and polymerization mechanisms. Prepared molecular wires indicated improved electronic properties evidenced by the electrochemical measurements revealing the energetically favored charge transporting polymer forms and the increased ratio between anodic and cathodic charge. Furthermore, we directly evidenced the presence of Ni 2+ salen polymer inside silica nanochannels by high-resolution X-ray photoelectron spectroscopy combined with a very low-energy argon ion beam sputtering, as well as by Atomic force microscopy and Transmission electron microscopy.
Domaines
Chimie analytiqueOrigine | Fichiers produits par l'(les) auteur(s) |
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