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Design principle for increasing charge mobility of π-conjugated polymers using regularly localized molecular orbitals.

Terao J, Wadahama A, Matono A, Tada T, Watanabe S, Seki S, Fujihara T, Tsuji Y - Nat Commun (2013)

Bottom Line: The zigzag wires exhibited higher intramolecular charge mobility than the corresponding linear wires.When the length of the linear region of the zigzag wires was increased to 10 phenylene-ethynylene units, the intramolecular charge mobility increased to 8.5 cm(2) V(-1) s(-1).Theoretical analysis confirmed that this design principle is suitable for obtaining ideal charge mobilities in π-conjugated polymer chains and that it provides the most effective pathways for inter-site hopping processes.

View Article: PubMed Central - PubMed

Affiliation: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan. terao@scl.kyoto-u.ac.jp

ABSTRACT
The feasibility of using π-conjugated polymers as next-generation electronic materials is extensively studied; however, their charge mobilities are lower than those of inorganic materials. Here we demonstrate a new design principle for increasing the intramolecular charge mobility of π-conjugated polymers by covering the π-conjugated chain with macrocycles and regularly localizing π-molecular orbitals to realize an ideal orbital alignment for charge hopping. Based on theoretical predictions, insulated wires containing meta-junctioned poly(phenylene-ethynylene) as the backbone units were designed and synthesized. The zigzag wires exhibited higher intramolecular charge mobility than the corresponding linear wires. When the length of the linear region of the zigzag wires was increased to 10 phenylene-ethynylene units, the intramolecular charge mobility increased to 8.5 cm(2) V(-1) s(-1). Theoretical analysis confirmed that this design principle is suitable for obtaining ideal charge mobilities in π-conjugated polymer chains and that it provides the most effective pathways for inter-site hopping processes.

No MeSH data available.


Related in: MedlinePlus

Calculated MSDs and length histograms of the planar segments.(a) MSDs for 10 typical out of configurations for both the para and meta(3) systems. (b) Length histograms of the planar segments in the para and meta(3) systems. Nplane is the number of benzene rings within a planar segment. The inset shows the time-averaged DOSs. In these simulations, a wave-packet energy of 0.5tc and a half-width of 0.015tc were used as the incoming wave packet, which corresponds to the experimental conditions for light irradiation with an energy of 2.5 eV, because tc is nearly equal to 2.5 eV in carbon systems.
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f5: Calculated MSDs and length histograms of the planar segments.(a) MSDs for 10 typical out of configurations for both the para and meta(3) systems. (b) Length histograms of the planar segments in the para and meta(3) systems. Nplane is the number of benzene rings within a planar segment. The inset shows the time-averaged DOSs. In these simulations, a wave-packet energy of 0.5tc and a half-width of 0.015tc were used as the incoming wave packet, which corresponds to the experimental conditions for light irradiation with an energy of 2.5 eV, because tc is nearly equal to 2.5 eV in carbon systems.

Mentions: Figure 5a shows the typical calculated MSDs of the para and meta(3) systems. The MSDs depend on the wire configurations; for instance, the wave-packet diffusion within a planar structure is faster than that in a non-planar structure. The meta(3) system was found to have much larger MSDs than the para-system. The average values of the mobilities for the para and meta(3) systems were calculated to be 5.4±1.4 and 7.2±2.0 cm2 V−1 s−1, respectively. Although the calculated mobilities of the para and meta(3) systems are quantitatively larger than the observed ones, the qualitative relationship of the mobilities for both systems is the same.


Design principle for increasing charge mobility of π-conjugated polymers using regularly localized molecular orbitals.

Terao J, Wadahama A, Matono A, Tada T, Watanabe S, Seki S, Fujihara T, Tsuji Y - Nat Commun (2013)

Calculated MSDs and length histograms of the planar segments.(a) MSDs for 10 typical out of configurations for both the para and meta(3) systems. (b) Length histograms of the planar segments in the para and meta(3) systems. Nplane is the number of benzene rings within a planar segment. The inset shows the time-averaged DOSs. In these simulations, a wave-packet energy of 0.5tc and a half-width of 0.015tc were used as the incoming wave packet, which corresponds to the experimental conditions for light irradiation with an energy of 2.5 eV, because tc is nearly equal to 2.5 eV in carbon systems.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3644079&req=5

f5: Calculated MSDs and length histograms of the planar segments.(a) MSDs for 10 typical out of configurations for both the para and meta(3) systems. (b) Length histograms of the planar segments in the para and meta(3) systems. Nplane is the number of benzene rings within a planar segment. The inset shows the time-averaged DOSs. In these simulations, a wave-packet energy of 0.5tc and a half-width of 0.015tc were used as the incoming wave packet, which corresponds to the experimental conditions for light irradiation with an energy of 2.5 eV, because tc is nearly equal to 2.5 eV in carbon systems.
Mentions: Figure 5a shows the typical calculated MSDs of the para and meta(3) systems. The MSDs depend on the wire configurations; for instance, the wave-packet diffusion within a planar structure is faster than that in a non-planar structure. The meta(3) system was found to have much larger MSDs than the para-system. The average values of the mobilities for the para and meta(3) systems were calculated to be 5.4±1.4 and 7.2±2.0 cm2 V−1 s−1, respectively. Although the calculated mobilities of the para and meta(3) systems are quantitatively larger than the observed ones, the qualitative relationship of the mobilities for both systems is the same.

Bottom Line: The zigzag wires exhibited higher intramolecular charge mobility than the corresponding linear wires.When the length of the linear region of the zigzag wires was increased to 10 phenylene-ethynylene units, the intramolecular charge mobility increased to 8.5 cm(2) V(-1) s(-1).Theoretical analysis confirmed that this design principle is suitable for obtaining ideal charge mobilities in π-conjugated polymer chains and that it provides the most effective pathways for inter-site hopping processes.

View Article: PubMed Central - PubMed

Affiliation: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan. terao@scl.kyoto-u.ac.jp

ABSTRACT
The feasibility of using π-conjugated polymers as next-generation electronic materials is extensively studied; however, their charge mobilities are lower than those of inorganic materials. Here we demonstrate a new design principle for increasing the intramolecular charge mobility of π-conjugated polymers by covering the π-conjugated chain with macrocycles and regularly localizing π-molecular orbitals to realize an ideal orbital alignment for charge hopping. Based on theoretical predictions, insulated wires containing meta-junctioned poly(phenylene-ethynylene) as the backbone units were designed and synthesized. The zigzag wires exhibited higher intramolecular charge mobility than the corresponding linear wires. When the length of the linear region of the zigzag wires was increased to 10 phenylene-ethynylene units, the intramolecular charge mobility increased to 8.5 cm(2) V(-1) s(-1). Theoretical analysis confirmed that this design principle is suitable for obtaining ideal charge mobilities in π-conjugated polymer chains and that it provides the most effective pathways for inter-site hopping processes.

No MeSH data available.


Related in: MedlinePlus