Photoresponsive ionic liquid crystals based on azobenzene guanidinium salts was written by Wuckert, Eugen;Harjung, Marc D.;Kapernaum, Nadia;Mueller, Carsten;Frey, Wolfgang;Baro, Angelika;Giesselmann, Frank;Laschat, Sabine. And the article was included in Physical Chemistry Chemical Physics in 2015.Product Details of 954-81-4 This article mentions the following:
The use of non-ionic LC phases as anisotropic matrixes for E/Z-isomerization of azo-guest mols. is often restricted due to limited solubilities and demixing effects. In this study we therefore employed an ionic liquid crystal (ILC) matrix to follow the photo-induced E/Z-isomerization of ionic mesogenic azobenzene guanidinium guests. The latter were prepared from 4-hydroxy-4′-(octyloxy)azobenzene, which was first treated with N-(bromoalkyl)phthalimides to introduce the spacer with varying chain length. Removal of phthalimide and final reaction with a formamidinium salt linked the ionic head group to the photoisomerizable azobenzene unit. Investigation of the mesomorphic behavior revealed for all azobenzene ILCs smectic A mesophases with high translational order parameters and partial bilayers, as could be stated by layer spacing d. Similar packing behavior was found for the solid state by X-ray crystal structure anal. E/Z-isomerization of azobenzene ILCs which were completely miscible with the ionic LC phase of C12MIM-Br as anisotropic host was induced by irradiation with UV light and the reisomerization observed by time-resolved UV-Vis spectroscopy. For comparison, water was used as isotropic host. Z/E-reisomerization activation energies exhibited similar values of 97-100 kJ mol-1 irresp. of spacer lengths and the type of host. The results demonstrate that a proper match of steric requirements of host and guest as well as layer spacings are needed for a decreased activation energy. In the experiment, the researchers used many compounds, for example, N-(5-Bromopentyl)phthalimide (cas: 954-81-4Product Details of 954-81-4).
N-(5-Bromopentyl)phthalimide (cas: 954-81-4) belongs to organobromine compounds. Organo bromine compounds are versatile compounds and are widely used in diverse fields. Organo bromine derivatives are used in the dye sector, as an indicator in analytical chemistry (Bromothymol blue is a popular indicator). In the pharmaceutical industry organo bromine derivatives are used as sedatives, vasodilators, antiseptic agents, and anticancer agents.Product Details of 954-81-4
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary