Light-driven molecular switch

Zhang C, Du MH, Cheng HP, Zhang XG, Roitberg AE, Krause JL (2004) Coherent electron transport through an azobenzene molecule a light-driven molecular switch. Phys Rev Lett 92(15) 158301... 

A. DelMedico, S. S. Fielder, A. B. P. Lever, and W. J. Pietro, Inorg. Chem., 34, 1507 (1995). Rational Design of a Light-Driven Molecular Switch Incorporating an Alizarin-Ru(bpy)2 Fragment. 

L. Green, Y. Li, T.J. White, A. Urbas, T. Running, Q. Li, Light-driven molecular switches with tetrahedral and axial chirality. Org. Biomol. Chem. 7, 3930-3933 (2009)... 

Scheme 3.34 Representative examples of light-driven molecular switches and motors.

Fig. 11 CD spectra of the four stages of switching of the light-driven molecular rotor.

Reviews on molecular switches and motors based on sterically hindered alkenes derived from naphtho[2,1 -6]thiopyrans <07JOC6635> and organic materials science <07JOC7477> have been published. A modified light-driven molecular motor has been found to function as a monolayer on quartz <07AG(E)1278>. 

The term photochromism can be defined as a light-driven reversible transformation between two isomers possessing different absorption spectra.111,21 The two isomers differ from one another not only in their absorption spectra, but also in their geometrical structures, oxidation/reduction potentials, refractive indices, and dielectric constants. When such photochromic chromophores are incorporated into functional molecules, such as polymers, host molecules, conductive molecular wires, or liquid crystals, the functions can be switched by photoirradiation.[3 61 Photostimulated reversible changes in refractive index can also be applied to optical waveguide switching.171 This chapter reviews applications of photochromic chromophores, especially diar-ylethene derivatives, in various photo switching molecular systems. 

Scheme 8 Light-driven multimode molecular switching of the electron transfer active dihydroazulene 31a.

Y. Wang, Q. Li, Light-driven chiral molecular switches or motors in liquid crystals. Adv. Mater. 24, 1926-1945 (2012)... 

Y. Wang, A. Utbas, Q. Li, Reversible visible-light tuning of self-organized helical superstructures enabled by unprecedented light-driven axially chiral molecular switches. J. Am. Chem. Soc. 134, 3342-3345 (2012)... 

---