Gelators azobenzene-based

Azobenzene-based gelators have been studied extensively, because spectroscopic properties of the azobenzene moiety afford useful information on how the molecules are assembled and how the gel is formed. A typical sample was azobenzene-appended cholesterol gelators 22a-e, in which azobenzene 7T-7T Stacking and cholesterol-cholesterol interaction cooperatively stabilize the organogel structure as described in Sect. 2.1.1 (Fig. 15) [12,13]. Hydro-... 

The synthesis and gelation properties of compounds 52-55, containing aromatic chromophores, were reported (Scheme 21). The central unit A of gela-tor 52 is based on two azobenzene chromophores that are connected by a central flexible diamino chain [76]. This compound was observed to gelate various organic solvents, such as 1-hexanol, 1-octanol, toluene, m-xylene, and p-xylene, under 1.0-5.0wt%. As observed in the case of ALS systems, CD spectroscopy pointed to the chiral orientation of 52 molecules within the gel aggregate and TEM photographs showed the occurrence of helical fibers. 

Fig. 29 Photo-responsive liquid-crystalline physical gel based on azobenzene-containing bis(amide)cyclohexane gelator...

Fig. 30 Photo-responsive liquid-crystalline physical gel based on azobenzene-containing bis(amide) gelator, and the schematic illustration of the mechanism for the light-induced reorganization in the liquid crystal gels and the grating formation...

Sakurai et al. have employed synchrotron SAXS to support a previously proposed model [54] for molecular arrangement in a helical fiber of an azobenzene-cholesterol-based gelator (6) [52a]. A hollow cylinder model exhibited better agreement with the experimental SAXS profile than a solid cylinder model. 

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