Photo-responsive groups

The transport number between anions can be changed by photoirradiation after introducing suitable photo-responsive groups into the membrane. Although the... 

Typical examples of reversible and irreversible photo-response groups. 

The great variety of incorporable building blocks also offers the synthetic chemist many potential structural and functional design possibilities. The insertion of, e.g., photo-responsive elements, groups with further supramolecular derivatization potential, or sulfonamide units which enable subsequent inter- and intramolecular linkage of catenanes and rotaxanes might render good service in the development of molecular switches [64] and devices [65]. 

Analogous photoresponsive peptide and polypeptide systems are being developed the photochemical properties of poly[W -p-(phenyl-azo)benzoyl-L-a,/8-diaminopropionic acid] have been examined, and the first example of photoregulation of permeability across a membrane has been achieved by the use of a new polyvinyl/poly-peptide graft copolymer composed of a photoresponsive copolypeptide branch from /3-p-phenylazobenzyl L-asparate and /3-benzyl L-asparate attached to a poly(Bu methacrylate) backbone.Papain activity has similarly been regulated by anchoring a photo-responsive azo group to the enzyme backbone. ... 

ABSTRACT. New photoresponsive crown ethers (Iff ") having a crown ring and an ammoniumalkyl (H3N (CH2)n"> n=4,6,10) group attached to the two sides of an azobenzene have been synthesized. Photo-responsive properties (thermal isomerization, metal extraction, membrane transport, etc.) were examined, and the results were compared with those of other photoresponsive crown ethers and complexons. 

Interagency Personnel Act (1970), 337 Intercenter Photo Working Group (IPWG) ambiguous threat response, 224-5 organizational learning lens, 250, 254,... 

In the fishes, as among most aquatic forms, xanthophylls are accumulated in preference to carotenes. But among the accumulators of xanthophylls, fishes form a special group since they accumulate only three lutein, taraxanthin, and astaxanthin. These carotenoids are accumulated particularly in the chromatophores of the skin where they play a part in photo-response. 

One advantage of the supramolecular polymers constructed by orthogonal assembly is their enhanced responsiveness to multiple external stimuli. Recently, a thermo- and photo-responsive supramolecular polymer based on pillar[5]arene was reported by Yang s group, ° where the anthracene group was used as the photo-responsive unit, and the pillar[5]arene/imidazole binding motif was employed as the thermo-responsive unit. When an anthracene-modified pillararene (7.27) was irradiated with UV light [1 >360 nm), the anthracene unit dimerized and the pillar[5]arene dimer... 

Polymers with photo-responsive terminal groups... 

Figure 4.7 exhibits examples of diblock copolymers with irreversible photo-response. Polymer 30 contains photolabile protecting groups attached to carboxylic groups in the side chains. Upon UV irradiation, photosolvolysis of the pyrenylmethyl ester occurs, 1-pyrenemethanol is cleaved from the polymer chain and carboxylic add groups are released. As a consequence, the hydrophobic block turns into a hydrophilic PMAA block. Core-shell micelles formed by 30 disappeared after irradiation with UV light at 365 nm. This design was further validated with other chromophores (polymers 31-34). °... 

Another photo-responsive organogel in a liquid crystalhne state was reported by Zhao s group [85]. A geiator 53 containing a photo-responsive azobenzene moiety and amide groups was dissolved in a cholesteric hquid... 

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