Spirobenzopyran membranes

The research was initiated by Kato et al. [51] in 1976, who used an acetyl cellulose film containing photochromic spirobenzopyran and phosphatidyl diloride. Figure 23 shows a schematic diagram of the apparatus used for the measurement of the membrane potential. The concentration ratio, y = C1/C2, of the electrolytes in compartments I and II is a parameter to vary the potential in the dark. In the dark before photoirradiation, the membrane exhibited a steady state potential difference Aq> of —28mv. The membrane potential shifted to — lOmv when the membrane was irradiated with ultraviolet light, and it reverted to the initial value upon visible irradiation. The change in the membrane potential was thus reversible. 

Fig. 24. Time responses of membrane potential across poly(vinyl chloride) membrane containing spirobenzopyran with a long alkyl chain upon UV and visible light irradiation [54], NaCl concentration in solution c, and C2 l M. a) UV irradiation from the side of Cj b) visible irradiation from the side of C2 c) UV irradiation from the side of Cj d) visible irradiation from the side of c ...

Membranes containing azobenzene-modified crown ether and crown ether linked spirobenzopyran also showed changes in the photostimulated membrane potential [55]. 2,3-Diphenylindenone oxide was also effective in changing the membrane potential of poly(vinyl chloride) by photoirradiation [56]. 

H. Sasaki, A. Ueno, J. Azai, and T. Osa, Benzo-15-crown-5 linked spirobenzopyran. I. Photocontrol of cation-binding ability and photoinduced membrane potential changes, Bull. Chem. Soc. Jpn. 59, 1953-1956(1986). 

Anzai J I, Osa T. 1994. Photosensitive artilidal membranes based on azobenzene and spirobenzopyran derivatives. Tetrahedron 50(14) 4039 4070. 

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