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Spiropyran Derivatives (spiropyran + derivative)

Distribution by Scientific Domains

Polymers and Materials Science	100%

Selected Abstracts

Multicolor Tunable Emission from Organogels Containing Tetraphenylethene, Perylenediimide, and Spiropyran Derivatives

ADVANCED FUNCTIONAL MATERIALS, Issue 19 2010
Qun Chen
Abstract A dendron-substituted tetraphenylethene low molecular weight gelator (LMWG)compound, LMWG1, is designed and investigated. Gelation-induced fluorescence enhancement is observed for the gel based on LMWG1 and its fluorescence can be reversibly tuned by varying the temperature of the ensemble. The photoinduced energy-transfer can occur between LMWG1 and PI2 (perylene diimide) in the gel phase, but it cannot occur in the corresponding solution. The emission color of the gel of LMWG1 and PI2 can be tuned from cyan, yellow, to red by varying the concentration of PI2. By taking advantage of the photochromic transformation of spiropyran, the emission color of the organogels based on LMWG1 and SP3 can be switched by alternating UV and visible-light irradiations. The emission color can also be tuned by varying the irradiation time. In this way, organogels based on LMWG1 with multiemission color can be achieved in the presence of SP3 after light irradiations. [source]

Columnar liquid-crystalline assemblies composed of spiropyran derivatives and sulfonic acids,

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 10 2008
Boon-Hooi Tan
Abstract A series of fan-shaped spiropyran derivatives with different length of alkyl chains has been synthesized. Liquid-crystalline (LC) assemblies of spiropyran derivatives have been formed by the addition of organic sulfonic acids such as trifluoromethylsulfonic acid, 10-camphorsulfonic acid, 4-methylbenzenesulfonic acid, and imidazolium-based ionic liquids (ILs) having a sulfonic acid group. Equimolar mixtures of a fan-shaped spiropyran derivative with the acidic imidazolium-based ILs exhibit columnar phases with wider LC temperature ranges as compared to those of other mixtures. The ionic interactions formed by the ionic imidazolium moieties should contribute to the stabilization of the columnar phases. On the other hand, equimolar mixtures of the spiropyran derivative with decane-1-sulfonic acid having a long alkyl chain and poly(4-styrenesulfonic acid) do not show mesomorphism. The chemical structure of organic sulfonic acids is a key factor for the induction and stabilization of the LC phases. Copyright © 2008 John Wiley & Sons, Ltd. [source]