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首页> 外文期刊>RSC Advances >Exploring the diethylaminoflavylium derivatives multistate system of chemical reactions in the presence of CTAB micelles: thermodynamic reversibility achieved through different kinetic pathways
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Exploring the diethylaminoflavylium derivatives multistate system of chemical reactions in the presence of CTAB micelles: thermodynamic reversibility achieved through different kinetic pathways

机译：在存在CTAB胶束的情况下探索二乙氨基黄酮衍生物的多态化学反应体系：通过不同的动力学途径实现热力学可逆性

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Aminoflavylium compounds like anthocyanins are involved in multiple reversible, pH-dependent chemical reactions. In very acidic media, the thermodynamically stable species is the flavylium cation, while it is trans-chalcone in near-neutral media. Different from anthocyanins, aminoflavylium compounds achieve the thermodynamic reversibility through different kinetic pathways depending on if the flavylium is transformed into the trans-chalcone upon a direct pH jump or the protonated trans-chalcone if converted into flavylium upon a reverse pH-jump. Three aminoflavylium compounds were prepared and investigated in the presence of CTAB micelles. Two of the compounds bear bridges linking rings C and B of the flavylium core, and the third lacks this bridge. The bridge has the effect of destabilizing the chalcones and the hemiketal. Only in the presence of CTAB micelles does the system respond to light stimuli, a powerful tool that provides a small cis–trans isomerization barrier for the three compounds. The relatively slow response of the system to direct and reverse pH jumps is due to the small mole fractions of Cc available for isomerization (giving Ct) and B available for dehydration (giving AH+). The mathematical expression that accounts for the pH-dependent kinetic processes was revisited to account for the consequences of amine protonation in very acidic media. The crystal structures of the compounds possessing the bridge were obtained, and for one of the compounds, two polymorphic forms were isolated from different crystallization solutions.
机译：诸如花青素之类的氨基黄酮类化合物参与多种可逆的，pH依赖的化学反应。在强酸性介质中，热力学稳定的物质是黄酮阳离子，而在近中性介质中是反式-查耳酮。与花青素不同，氨基黄酮化合物通过不同的动力学途径实现热力学可逆性，这取决于黄酮在直接pH跃迁或质子化的 trans -转化为 trans -查耳酮。查尔酮（如果反向pH跃迁转化为黄酮）。制备了三种氨基黄酮化合物，并在存在CTAB胶束的情况下进行了研究。其中两种化合物带有连接黄酮核心的环C和B的桥，而第三种则没有该桥。这座桥的作用是破坏了查尔孔和半桥的稳定性。只有在存在CTAB胶束的情况下，系统才能对光刺激作出反应，光刺激是一种强大的工具，可为三种化合物提供小的 cis - trans 异构化障碍。系统对pH值正向和反向跃迁的响应相对较慢，这是由于Cc的小摩尔分数可用于异构化（给定Ct），而B可用于脱水（给定AH + ）。重新考虑了pH依赖的动力学过程的数学表达式，以说明在极酸性介质中胺质子化的后果。获得具有桥的化合物的晶体结构，并且对于一种化合物，从不同的结晶溶液中分离出两种多晶型形式。

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