Molecular gears

J. A Swift, A M. Reynolds, M. D. Ward, "Cooperative host-guest recognition in crystalline clathrates steric guest ordering by molecular gears , Chem Mater. 1998, 10, 4159-4168. 

Molecular gearing systems are the first successful examples of rotary molecular devices engineered and synthesized using conventional chemistry. At the... 

The major efforts aimed at synthesizing molecular gears have been focused on triptycene derivatives. Triptycene (Tp), a rigid molecular unit with three blades each composed of a benzene ring, represents a molecular mimic of a gearing element [21]. The use of triptycenes as molecular gears (Fig. 2) has been studied since the 1970s mostly by Mislow and Iwamura [20],... 

Fig. 7, The Molecular Gear Shift model showing the positions of the S, energies of the xanthophyll cycle carotenoids relative to chlorophyll a. Antheraxanthin and lutein (not shown) are isoenergetic with chlorophyll a (Frank et al, 1994,1996).

Xian Y., Mao, C. (2004). Molecular gears a pair of DNA circles continuously rolls against each other. J Am Chem Soc 126, 11410-11411. 

Early in 1967, a molecular propeller-like compound was reported by Akkerman et al. In 1981, Mislow et al. synthesized a molecular gear system.In these systems, the two brakes or gears move cooperatively, and the relative movements of the two gears can be induced by the hit of solvent molecules. However, because the hit of the solvent molecules are aU spontaneous, these cannot be considered as molecular motors due to the random movements of the rotor in different directions. 

Clayden J. and Pink J.H. 1998. Concerted rotation in a tertiary aromatic amide towards a simple molecular gear. Ang. Chem. Int. Ed. Engl. 37 1937-1939. 

Cozzi E, Guenzi A., Johnson C.A., Mislow K., HounsheU W.D., and Blount J.F. 1981. Stereoisomerism and correlated rotation in molecular gear systems. Residual diastereomers of bis(2,3-dimethyl-9-triptycyl)methane. J. Am. Chem. Soc. 103 957-958. 

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