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Bridge- and solvent-mediated intramolecular electronic communications in ubiquinone-based biomolecular wires.

Liu XY, Ma W, Zhou H, Cao XM, Long YT - Sci Rep (2015)

Bottom Line: We found that the bridges linkers have a significant effect on the electronic communications between the two peripheral ubiquinone moieties and solvents effects are limited and mostly depend on the nature of solvents.The DFT calculations also demonstrates the effect of solvents on the latter two-electron transfer of Bis-CoQ0s is more significant than the former two electrons transfer as the observed electrochemical behaviors of three Bis-CoQ0s.In addition, the electrochemistry and theoretical calculations reveal the intramolecular electronic communications vary in the four-electron redox processes of three Bis-CoQ0s.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Advanced Materials &Department of Chemistry, East China University of Science and Technology, Shanghai 200237, P. R. China.

ABSTRACT
Intramolecular electronic communications of molecular wires play a crucial role for developing molecular devices. In the present work, we describe different degrees of intramolecular electronic communications in the redox processes of three ubiquinone-based biomolecular wires (Bis-CoQ0s) evaluated by electrochemistry and Density Functional Theory (DFT) methods in different solvents. We found that the bridges linkers have a significant effect on the electronic communications between the two peripheral ubiquinone moieties and solvents effects are limited and mostly depend on the nature of solvents. The DFT calculations for the first time indicate the intensity of the electronic communications during the redox processes rely on the molecular orbital elements VL for electron transfer (half of the energy splitting of the LUMO and LUMO+1), which is could be affected by the bridges linkers. The DFT calculations also demonstrates the effect of solvents on the latter two-electron transfer of Bis-CoQ0s is more significant than the former two electrons transfer as the observed electrochemical behaviors of three Bis-CoQ0s. In addition, the electrochemistry and theoretical calculations reveal the intramolecular electronic communications vary in the four-electron redox processes of three Bis-CoQ0s.

No MeSH data available.


CV and DPV curves of 1.0 mM Bis-CoQ0 1 (A and B),Bis-CoQ0 2 (C and D) and Bis-CoQ0 3 (E and F)obtained at a glassy carbon electrode in distilled THF (black line),CH2Cl2 (red line), CH3CN (blue line),DMF (orange line) and DMSO (pink line) containing 0.1 M TBAP atscan rates 0.010 Vs−1.
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f4: CV and DPV curves of 1.0 mM Bis-CoQ0 1 (A and B),Bis-CoQ0 2 (C and D) and Bis-CoQ0 3 (E and F)obtained at a glassy carbon electrode in distilled THF (black line),CH2Cl2 (red line), CH3CN (blue line),DMF (orange line) and DMSO (pink line) containing 0.1 M TBAP atscan rates 0.010 Vs−1.

Mentions: As shown in Fig. 4, for Bis-CoQ0 1, solventeffects on the third step reduction process are more significant than the firstand second reduction steps and the maximal potential shift for the threereduction peaks are 50 mV, 106 mV and 362 mVin the five solvents, respectively (TableS2). The similar phenomenon appears in Bis-CoQ0 2 andBis-CoQ0 3, where solvent effects on the second reduction peakare more appreciable than the first reduction step and the maximal potentialshift for two reduction peaks are 92 mV, 325 mV and81 mV, 181 mV, respectively (Table S3 and S4). These results were confirmedby previous work that the solvent effect is minor for monoradicals so long as atetra-alkylammonium salt is used as the supporting electrolyte and the effectsis more significant on latter electron transfer processes that mainly rely onthe nature of solvents (i.e. polarity, donor number)34.These electrochemical results also reveal that the solvent effect on theintramolecular electronic communication is week, especially the splitting of theformer two-electron transfer. Even so, the solvents effect on the electroniccommunications of Bis-CoQ0 2 is more interesting. From the DPV curvesof Fig. 4D, the splitting of first reduction peak ofBis-CoQ0 2 shows the different divisive degree in varioussolvents. This reduction peak splits into two peaks inCH2Cl2 and DMF indicating that the monoradical anionof Bis-CoQ0 2 is greater stable in CH2Cl2 andDMF and has longer lift time35.


Bridge- and solvent-mediated intramolecular electronic communications in ubiquinone-based biomolecular wires.

Liu XY, Ma W, Zhou H, Cao XM, Long YT - Sci Rep (2015)

CV and DPV curves of 1.0 mM Bis-CoQ0 1 (A and B),Bis-CoQ0 2 (C and D) and Bis-CoQ0 3 (E and F)obtained at a glassy carbon electrode in distilled THF (black line),CH2Cl2 (red line), CH3CN (blue line),DMF (orange line) and DMSO (pink line) containing 0.1 M TBAP atscan rates 0.010 Vs−1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4440530&req=5

f4: CV and DPV curves of 1.0 mM Bis-CoQ0 1 (A and B),Bis-CoQ0 2 (C and D) and Bis-CoQ0 3 (E and F)obtained at a glassy carbon electrode in distilled THF (black line),CH2Cl2 (red line), CH3CN (blue line),DMF (orange line) and DMSO (pink line) containing 0.1 M TBAP atscan rates 0.010 Vs−1.
Mentions: As shown in Fig. 4, for Bis-CoQ0 1, solventeffects on the third step reduction process are more significant than the firstand second reduction steps and the maximal potential shift for the threereduction peaks are 50 mV, 106 mV and 362 mVin the five solvents, respectively (TableS2). The similar phenomenon appears in Bis-CoQ0 2 andBis-CoQ0 3, where solvent effects on the second reduction peakare more appreciable than the first reduction step and the maximal potentialshift for two reduction peaks are 92 mV, 325 mV and81 mV, 181 mV, respectively (Table S3 and S4). These results were confirmedby previous work that the solvent effect is minor for monoradicals so long as atetra-alkylammonium salt is used as the supporting electrolyte and the effectsis more significant on latter electron transfer processes that mainly rely onthe nature of solvents (i.e. polarity, donor number)34.These electrochemical results also reveal that the solvent effect on theintramolecular electronic communication is week, especially the splitting of theformer two-electron transfer. Even so, the solvents effect on the electroniccommunications of Bis-CoQ0 2 is more interesting. From the DPV curvesof Fig. 4D, the splitting of first reduction peak ofBis-CoQ0 2 shows the different divisive degree in varioussolvents. This reduction peak splits into two peaks inCH2Cl2 and DMF indicating that the monoradical anionof Bis-CoQ0 2 is greater stable in CH2Cl2 andDMF and has longer lift time35.

Bottom Line: We found that the bridges linkers have a significant effect on the electronic communications between the two peripheral ubiquinone moieties and solvents effects are limited and mostly depend on the nature of solvents.The DFT calculations also demonstrates the effect of solvents on the latter two-electron transfer of Bis-CoQ0s is more significant than the former two electrons transfer as the observed electrochemical behaviors of three Bis-CoQ0s.In addition, the electrochemistry and theoretical calculations reveal the intramolecular electronic communications vary in the four-electron redox processes of three Bis-CoQ0s.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Advanced Materials &Department of Chemistry, East China University of Science and Technology, Shanghai 200237, P. R. China.

ABSTRACT
Intramolecular electronic communications of molecular wires play a crucial role for developing molecular devices. In the present work, we describe different degrees of intramolecular electronic communications in the redox processes of three ubiquinone-based biomolecular wires (Bis-CoQ0s) evaluated by electrochemistry and Density Functional Theory (DFT) methods in different solvents. We found that the bridges linkers have a significant effect on the electronic communications between the two peripheral ubiquinone moieties and solvents effects are limited and mostly depend on the nature of solvents. The DFT calculations for the first time indicate the intensity of the electronic communications during the redox processes rely on the molecular orbital elements VL for electron transfer (half of the energy splitting of the LUMO and LUMO+1), which is could be affected by the bridges linkers. The DFT calculations also demonstrates the effect of solvents on the latter two-electron transfer of Bis-CoQ0s is more significant than the former two electrons transfer as the observed electrochemical behaviors of three Bis-CoQ0s. In addition, the electrochemistry and theoretical calculations reveal the intramolecular electronic communications vary in the four-electron redox processes of three Bis-CoQ0s.

No MeSH data available.