Ezhov Roman N, Rozhkov Vladimir V, Majjigapu Janaki R R, Kutateladze Andrei G
Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80208.
J Sulphur Chem. 2008;29(3-4):389-400. doi: 10.1080/17415990802027289.
Novel photolabile amphiphiles containing thioxanthone-based fluorogenic caging groups are developed. Photoinduced fragmentation in dithiane-thioxanthone adducts was demonstrated to occur with 100% quantum efficiency at λ ~ 320 nm and more than 50% at λ ~ 360 nm. A plausible mechanism involves homolytic fission of a carbon-carbon single bond in the excited thioxanthone followed by disproportionation via hydrogen transfer. The critical feature of the system is that fluorescence of a substituted thioxanthone is recovered as a result of photofragmentation, making dithiane-thioxanthone adducts efficient fluorogenic caging groups. Photolabile amphiphiles containing these fluorogens are synthesized and their photoinduced disassembly is probed while following the fluorescence recovery. This methodology allows for destabilizing supramolecular assemblies of amphiphiles and at the same time offers a feedback mechanism for monitoring the process by fluorescence.
开发了含有基于硫杂蒽的荧光笼蔽基团的新型光不稳定两亲分子。已证明二硫烷 - 硫杂蒽加合物在λ320 nm处发生光诱导裂解，量子效率为100%，在λ360 nm处超过50%。一种合理的机制涉及激发态硫杂蒽中碳 - 碳单键的均裂，随后通过氢转移发生歧化反应。该体系的关键特征是，由于光裂解，取代硫杂蒽的荧光得以恢复，使得二硫烷 - 硫杂蒽加合物成为高效的荧光笼蔽基团。合成了含有这些荧光团的光不稳定两亲分子，并在跟踪荧光恢复的同时探究了它们的光诱导分解。这种方法能够使两亲分子的超分子组装体不稳定，同时提供一种通过荧光监测该过程的反馈机制。
