Synthesis and Thermal Responses of Polygonal Poly(ethylene glycol) Analogues
| Autor: | Shunichi Kawasaki, Fumi Nagatsugi, Takahiro Muraoka, Kazushi Kinbara, Tsutomu Hamada, Kazuki Shigyou |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Conformational change
Molecular Structure Organic Chemistry Temperature technology industry and agriculture 02 engineering and technology General Chemistry macromolecular substances 010402 general chemistry 021001 nanoscience & nanotechnology Ring (chemistry) 01 natural sciences Biochemistry Polyethylene Glycols 0104 chemical sciences Tetragonal crystal system chemistry.chemical_compound Crystallography chemistry Intramolecular force PEG ratio Molecule 0210 nano-technology Dispersion (chemistry) Ethylene glycol |
| Zdroj: | Chem. Asian J.. 11(No. 7):1028-1035 |
| Popis: | As a new type of topological poly(ethylene glycol) (PEG) analogue, a series of polygonal PEGs with digonal to hexagonal structures were developed. Polygonal PEGs with structures between the digonal and tetragonal types showed molecular-level dispersion in water at 20 °C, whereas the pentagonal and hexagonal PEGs aggregated, which is suggestive of enhanced hydrophobicity by ring expansion. Heating induced conformational changes in the polygonal PEGs and increased their hydrophobicity. Among the polygonal PEGs, only the trigonal and hexagonal PEGs showed a distinct thermal response to form and increase the size of the aggregates, respectively. Given that tetragonal and pentagonal PEGs only marginally responded to heat treatment, the thermal responses are likely due to a topological effect. At low temperatures, the larger polygonal PEGs are more restricted despite the expanded rings. The trigonal PEG showed the largest change in mobility, whereas the tetragonal PEG exhibited the smallest change. Hence, the topology of the polygonal PEGs influences the intramolecular packing and the local dynamics. |
| Databáze: | OpenAIRE |
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