Control of headgroup orientation of monolayer by glucolipid
作者:Koji Kano、Taizo Ishimura、Shizunobu Hashimoto
DOI:10.1021/j100173a052
日期:1991.10
The mixed monolayers of 1-laurylpyrene-8-carboxylic acid (LP8C) and glucolipids have been studied by measuring pressure-area isotherms and fluorescence spectral changes during compression. LP8C itself does not form a monolayer on pure water and is dispersed as a solid which shows a blue-shifted excimer-like fluorescence at around 470 nm. The 1:1 mixture of LP8C and stearyl alpha-D-glucopyranoside (SGP), however, forms a relatively stable monolayer having a collapse pressure of 36 mN/m. The fluorescence maximum of the LP8C-SGP monolayer is 520 nm. Glycerol alpha-monostearate (GMS), stearyl tetrakis(2,3,4,6-O-methyl)-alpha-D-glucopyranoside (MeSGP), and stearyl tetrakis(2,3,4,6-O-acetyl)-alpha-D-glucopyranoside (AcSGP) do not show the same effect as does SGP, the fluorescence maxima of the mixed monolayers of LP8C and these hydrocarbons being 470 nm. These results can be explained on the basis that the pyrene chromophores are well ordered at the air-water interface by hydrogen bonding between the carboxyl groups of LP8C and the hydroxyl groups of SGP. The fluorescence of dansyllaurylamine suggests that the dehydration from the headgroups of SGP readily occurs during the compression of the monolayer. The easy dehydration from the headgroups may be essential to from the intermolecular hydrogen bonds at the interface.
Pyrene-Derived Novel One- and Two-Component Organogelators
作者:P. Babu、N. M. Sangeetha、P. Vijaykumar、Uday Maitra、Kari Rissanen、A. R. Raju
DOI:10.1002/chem.200204459
日期:2003.5.9
A new class of alkyl-chain-appended pyrene derivatives 4-14 were synthesized and evaluated for their gelation abilities. Depending on the nature of the linking group, these compounds gelated a number of organic solvents, either in the presence or in the absence of the acceptor molecule 2,4,7-trinitrofluorenone (TNF). Compounds with ester, ether, or alkyl linkages gelated a number of hydroxylic and