Blue-Colored Donor-Acceptor [2]Rotaxane

1. Blue-Colored Donor-Acceptor [2]Rotaxane Taichi Ikeda, Ivan Aprahamian, and J. Fraser Stoddart, Org. Lett.2007, 9, 1481-1484. Kazuhiro IKUTA Tobe Lab.

2. Contents □Introduction 　・Structure of Rotaxane 　・Color of the CT complex 　・Idea of RGB dye 　・Purpose of this Work □Results and Discussion 　・Synthesis of Rotaxane 　・UV-vis Spectra 　・Electrochemical Properties □Summary

3. Structure of Rotaxane Rotaxane Stopper unit Dumbbell component Ring component ☆ A rotaxane is a mechanically interlocked molecular architecture consisting of a dumbbell-shaped component that is threaded through a ring component. ☆ The ring component can not be pulled out because the bulky substituents called ‘Stoppers’ exist at both edges of axle, then this component is called ‘Dumbbell’. Shuttling (moving in parallel)

4. Color of CT Complex Stabilization by Coulombic interaction

5. Idea of RGB dye Color change scheme of the RGB dye ・The color of this three-station catenane changes as a function of the CBPQT4+ ring location which, in principle, can be controlled by the oxidation of each station in turn. Stoddart, J. F. et al.J. Am. Chem. Soc. 2005, 127, 15994.

6. Purpose of this Work Green ≡ Stoddart, J. F. et al.Org. Lett, 2007, 9, 1287. Red Purpose of this Work ・Synthesis of blue-colored rotaxane ・investigation of its optical and electrochemical properties New guest compound

7. Synthesis of the Blue-colored [2]Rotaxane (Orange wax) (White powder) (Blue solid)

8. UV-vis Absorption Spectra UV-vis absorption spectra (rt, MeCN, 1 mM) of (a) a 1:1 mixture of DFBZ and CBPQT·4PF6, (b) a 1:1 mixture of DFBZ-TEG and CBPQT·4PF6, and (c) the blue-colored [2]rotaxane 1·4PF6. A photograph of the blue-colored [2]rotaxane solution is shown in the inset. The introduction of tetraethyleneglycol chains ⇒a change of the maximum absorption wavelength (λmax) from 570 to 610 nm. ⇒the HOMO energy level of DFBZ changes as a direct result of the alkylation

9. Cyclic Voltammetry +0.95 +0.76 The redox potentials of (a) are higher than those of (b). ⇒consistent with UV-vis results. +0.83 +0.65 +1.02 distorting ⇒assuming that the flexible linker enables the ring to move freely around the station. ⇒the broadening of the redox CV peak +0.85

10. Cyclic Voltammetry +0.83 +0.65 Shifting in the same magnitude ⇒ring translocatedslightly from the DFBZ station to TEG spacer ⇒influence of the CBPQT4+ ring to second redox potential +1.02 +0.85

11. Cyclic Voltammetry Stoddart, J. F. et al. Org. Lett.2006, 8, 2205 (ⅰ) (ⅱ)(ⅲ)

12. Summary • We have designed, synthesized, and characterized DFBZ-TEG and the [2]rotaxane consisting of DFBZ-TEG and CBPQT4+. • We confirmed the blue color of the CT absorption band between DFBZ-TEG and CBPQT・4PF6. • The acquired data on model compounds –absorption spectra, and electrochemical properties – indicates that the design of an RGB dye using the discussed donor –acceptor motif is attainable.

13. 740 nm 610 nm 500 nm 補色

14. Introduction ・The color of the complex with CBPQT4+ as the host is determined by the wavelength of the CT absorption band. ・The absorption wavelength depends on the energy gap between the LUMO of CBPQT4+ and the HOMO of the guest molecule. We can generate a range of different colors by altering the HOMO energy level of the guest molecules. Guest