Journal article
Crystalline self-assembly into monolayers of folded oligomers at the air-water interface
Insertion of the 115-bis(ethynylene)benzene unit as a rigid spacer into a linear alkyl chain, thus separating the two resulting stems by 9 Angstrom, induces chain folding at the air-water interface. These folded molecules self-assemble into crystalline monolayers at this interface, with the plane of the folding unit almost perpendicular to the water surface, as determined by synchrotron grazing-incidence X-ray diffraction.
Three distinct molecular shapes, of the types U, inverted U, and M, were obtained in the two-dimensional crystalline state, depending upon the number of spacer units, and the number and position of the hydrophilic groups in the molecule. The molecules form ribbons with a higher crystal coherence in the direction of stacking between the molecular ribbons, and a lower coherence along the ribbon direction.
A similar molecule, but with a spacer unit that imposes a 5 Angstrom separation between alkyl chains, yields the conventional herringbone arrangement.
Language: | English |
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Year: | 2000 |
Pages: | 2173-2183 |
ISSN: | 15213765 and 09476539 |
Types: | Journal article |
DOI: | 10.1002/1521-3765(20000616)6:12<2173::AID-CHEM2173>3.0.CO;2-E |