Host components photoisomerizable

Affinity Interactions at Interfaces Using Immobilized Photoisomerizable Host Components... 

RECOGNITION PHENOMENA AT SURFACES USING PHOTOISOMERIZABLE GUEST OR HOST COMPONENTS... 

The immobilization of photoisomerizable host molecules onto an electrode surface can be used for the construction of novel ion-selective electrodes. A photoisomerizable calix[4]arene derivative was incorporated into a polymeric membrane on an electrode surface and the two different isomeric states of the host molecule provided responses selective to Li" or Na" ions depending on the state.Another photoisomerizable host molecule has been constructed from spiropyran and crown-ether subunits. Different binding affinities for Li were found depending on the isomeric state of the photoisomerizable component (26). The researchers suggested that this effect was caused by the coordination of the Li ion to the 0 of the zwitterionic merocyanine-form (Figure 7.29). The photocontrolled host molecules were immobilized in a polymeric film onto an electrode surface, resulting in a photochemically switchable ion-selective electrode. 

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