Ionochromic properties

Highly hydrophilic polymers derivatized with oligoethers chains have been prepared from 45. These polymers show electroactivity in aqueous medium and present cation recognition properties. Moreover, they constitute a unique example of polymers with solid state ionochromic properties (see Section 13.4.1.1) [146]. The synthesis of 54 bearing perfluoro chains has also been reported starting from 45 and its related polymer has been investigated for electrochromic application [147]. 

Poly(methylsilylene-/>-phenylene)s carrying Si-linked benzocrown ether and ethoxy pendant groups 86 (parameters x and y are associated with the benzo crown vs. ethoxy ratio present in the polymer) showed ionochromic behavior, and responded selectively to alkali and alkaline earth metal ions in the emission spectra, depending on the crown ether ring size. These polymers also display solvatochromic properties by changing the solvent polarity in the absence of metal ions <2006OM2225>. 

Chemichromism characterizes materials that are able to change their optical properties when their chemical environment changes. In particular, it includes ionochromism, halochromism and solvatochromism. 

Polythiophenes are not only interesting because of their electrical properties. On oxidation (p-doping), the electrical conductivity can be enhanced from about 10 S.cm (pristine material) up to several thousand S.cm in the oxidized form. This layers of polythiophenes are also of interest due to their large number of special electrophysical properties Thermochromism, electrochromism, solvatochromism, ionochromism, color changes under pressure and effected by electricity. 

Polymer 26 does exhibit ion-binding properties, and an ionochromic response occurs upon exposure to Li" in acetonitrile and leads to a blue shift of up to 11 nm [75]. A dramatic chemoselective response to Pb in... 

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