Self-Assembled Microstructures from a Polymerizable Ammonium Surfactant: Di(Hexacosa-12,14-diynyl)dimethylammonium Bromide.

摘要

We have observed the formation of some unusual microstructures produced from di(hexacosa-12.14-diynyl)dimethylammonium bromide (DHDAM) (1). Our earlier studies demonstrated that diacetylenic phospholipids produced tubular microstructures as well as vesicles from aqueous dispersion. The formation of tubules both from diacetylene containing phosphatidylcholine (PC) and a non-diacetyleneglutamate-based amphiphile has through to proceed via precipitation from solvent solution as helices which grow into continuous cylinders. The chiral centre of these molecules can be correlated with the handedness of the overall molecular assembly. It is clear that the diacetylenic moiety has an important role in the formation of these microstructures since only those PCs which contain the diacetylene moiety in the alkyl chains form tubules and helices. Diacetylenic racemates have also been observed to torm tubules and helices with both right- and left-handed structures. The presence of the diacetylenic moiety also has been shown for other materials including phosphatidylcholines to allow a 1.4-polymerization to occur upon irradiation by 254 nm light. (JS)