Molecular loop lock

Scheme 4.7 A molecular loop lock that responds to chemical and redox stimuli.

Kim et al. reported a redox-driven molecular machine (Figure 46) based on a host-stabilized charge-transfer complex acting as a molecular loop lock. The molecular machine was based on a pseudorotaxane comprising a CB[8] ring and an axle component bearing a m-electron-deficient paraquat unit, a rr-electron-rich naphthalene unit. 

Jeon WS, Kim E, Ko YH, Hwang I, Lee JW, Kim S-Y, Kim H-J, Kim K. Molecular loop lock a redox-driven molecular machine based on a host-stabilized charge-transfer complex. Angew Chem Int Ed 2005 44 87-91. 

PQ2+. This molecular machine behaves as a molecular loop Later, the same group constructed another molecular lock, and shows a new way to construct CB-based molec- machine (Figure 47) based on reversible end-to-interior and... 

Fig. 5.52. Long-term stabilization of the laser wavelength locked to a reference FPI that in turn is locked by a digital servo loop to a molecular transition...

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