"Extra stabilisation" of a pyrene based molecular couple by γ-cyclodextrin in the excited electronic state
"Extra stabilisation" of a pyrene based molecular couple by γ-cyclodextrin in the excited electronic state
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DOI：
10.1039/c2cp41921a
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发表时间：
2012-01-01
影响因子：
3.3
通讯作者：
Purkayastha, Pradipta
中科院分区：
文献类型：
--
作者：
Ghosh, Prasun;Mandal, Soumik;Purkayastha, Pradipta
合成了两种氨基硫脲和氨基脲功能化的芘标记席夫碱化合物。化合物中的芘部分导致在激发电子态下在水性介质中形成π-π偶联络合物。添加的γ-环糊精允许芘头掺入其较低极性的核内，并促进化合物的硫代和氧代基团与其边缘羟基的氢键合，以“稳定”单体。这是由FT-IR和吸收光谱证实。通过改变实验条件，稳定的单体导致稳定的准分子的形成，如通过稳态和时间分辨荧光光谱法所监测的。所提出的模型的稳定的席夫碱单体已被证明通过比较与两个控制化合物的荧光光谱的变化。目前的工作报告向前迈出了一步，提出了一个简单的主客体方法，以额外稳定的芘基准分子，可以生物利用。
Two thiosemicarbazide and semicarbazide functionalized pyrene labeled Schiff base compounds have been synthesized. The pyrene moieties in the compounds result in formation of pi-pi coupled complexes in aqueous medium in the excited electronic state. Added gamma-cyclodextrin allows incorporation of the pyrene head inside its less polar core and promotes hydrogen bonding of the thio and oxo groups of the compounds with its rim hydroxyl groups to "stabilise" the monomers. This is confirmed by FT-IR and absorption spectroscopy. The stabilised monomers lead to formation of stabilised excimers as monitored by steady state and time-resolved fluorescence spectroscopy through varying the experimental conditions. The proposed model for the stabilisation of the Schiff base monomers has been evidenced by comparing with the fluorescence spectroscopic changes of two control compounds. The present work reports a step ahead toward proposing a simple host-guest method to extra stabilise the pyrene based excimers that can be biologically utilised.