Dynamics of capsuleplex formed between octaacid and organic guest molecules - Photophysical techniques reveal the opening and closing of capsuleplex
Dynamics of capsuleplex formed between octaacid and organic guest molecules - Photophysical techniques reveal the opening and closing of capsuleplex
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DOI：
10.1139/v10-104
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发表时间：
2011-02-01
影响因子：
1.1
通讯作者：
Ramamurthy, V.
中科院分区：
文献类型：
--
作者：
Jayaraj, Nithyanandhan;Jockusch, Steffen;Ramamurthy, V.
这份手稿是关于由有机客体分子和两个空穴分子组成的胶囊复合体的打开和关闭，该分子被称为辛酸(OA)。胶囊复合体通过弱相互作用在水中松散地结合在一起。我们通过监测胶囊中9个不同客体分子被溶解在胶囊周围水中的分子氧对激发的单线态和(或)三线态的猝灭来研究OA胶囊复合体的打开和关闭。通过监测水中不同氧浓度下客体分子的荧光/磷光强度或激发态寿命，估算了被激发客体分子的氧猝灭速率常数。客体分子的选择使得人们可以在0.05-922亩的时间范围内探测S的开合过程。我们认为，氧气猝灭常数反映了被包裹在OA胶囊复合体中的客体对氧气的可获得性，而这反过来又取决于胶囊的开合速率常数。根据猝灭的研究，我们得出结论，S的寿命小于5亩的客人是无法接触到氧气的。本报告提出的结果表明，开放的范围和时间范围取决于客人。
This manuscript is concerned with the opening and closing of a capsuleplex made up of organic guest molecules and two cavitand molecules known as octaacid (OA). The capsuleplex is loosely held together in water through weak interactions. We have investigated the opening-closing of the OA capsuleplex by monitoring the quenching of excited singlet and (or) triplet states of nine different guest molecules encapsulated within a capsule by molecular oxygen that is dissolved in water surrounding the capsule. The rate constants for oxygen quenching of the excited guest molecules were estimated by monitoring the intensity of fluorescence/phosphorescence or lifetimes of excited states of guest molecules in the presence of different concentrations of oxygen in water. Guest molecules were chosen such that one could probe the opening-closing process during a time range of 0.05 to 922 mu s. We believe that the oxygen quenching constant reflects the accessibility of oxygen to the guest enclosed within the OA capsuleplex, and this in turn depends on the capsule opening-closing rate constant. Based on the quenching studies, we conclude that guests whose lifetimes are shorter than 5 mu s are inaccessible to oxygen. Results presented in this report suggest that the extent and time scale for opening depends on the guest.