431039-52-0Relevant articles and documents
A Cholesterol Containing pH-Sensitive Bistable [2]Rotaxane
Berg, Martin,Nozinovic, Senada,Engeser, Marianne,Lützen, Arne
, p. 5966 - 5978 (2015/09/22)
A non-symmetrical pH-sensitive bistable [2]rotaxane that bears a cholesterol unit and a tetraphenylmethane group as stopper groups was designed and synthesized in 18 steps. The successful formation of the rotaxane was proven by NMR spectroscopy and MS/MS. Besides a permanent cationic alkylated triazolium unit, the axle contains a secondary amine that can act as a second pH-sensitive binding site for a crown ether. Depending on the protonation state of this amine function, the crown ether reversibly changes its position by moving between the two binding sites along the axle, as revealed by NMR spectroscopy. A pH-sensitive bistable [2]rotaxane was synthesized and characterized by NMR spectroscopy and MS/MS. Besides an alkylated triazolium ion, the axle contains a secondary amine that acts as a second pH-sensitive binding site for a crown ether. Depending on the protonation state of this amine function, the crown ether reversibly changes its position by moving between two binding sites on the axles.
Nanostructured columnar and cubic liquid-crystalline assemblies consisting of unconventional rigid mesogens based on triphenylmethanes
Hatano, Tsukasa,Kato, Takashi
, p. 8368 - 8380 (2008/12/21)
Liquid-crystalline (LC) molecules of unconventional shapes that form columnar and micellar cubic structures have been synthesized using triarylmethyl moieties as building blocks. The molecules have bowl- and dumbbell-shape. Despite the rigidity and bulkiness of the triarylmethyl moieties, the molecules form columnar and micellar cubic LC phases. The bowl-shaped molecules containing one triarylmethyl moiety show LC phases. The LC temperature ranges of the dumbbell-shaped molecules containing two triarylmethyl moieties connected by rigid rods are wider than those of bowl-shaped molecules containing one triarylmethyl moiety. The UV-vis spectroscopy of the dumbbell-shaped molecules having a terphenyl moiety reveals that the terphenyl moieties aggregate in the mesophase.