作者:Youngkook Kim、Young Ho Ko、Minseon Jung、Narayanan Selvapalam、Kimoon Kim
DOI:10.1039/c1pp05055a
日期:2011.9
A new photo-switchable “on-off” host-guest system comprising cucurbit[7]uril (CB[7]) and a photoresponsive cinnamamide derivative (trans-(3-phenyl-acryloylamino)-acetic acid, E-1) is studied. The cinnamamide derivative and CB[7] forms a stable 1:1 host-guest complex (CB[7]-E-1) with a high binding constant (K = 2.1 × 104 M-1). Irradiation of UV light (300 nm) to an aqueous solution of CB[7]-E-1 induces the E- to Z-conformational change of the cinnamamide derivative, which then leads to the dissociation of the complex as evidenced by UV-visible and 1H-NMR spectroscopy. The reverse process, photo-induced host-guest complex formation between CB[7] and Z-1 is achieved by irradiation of UV light at 254 nm. The photo-switchable “on-off” host-guest system shows high reversibility and switching efficiency, which makes it potentially useful in designing photoresponsive gating systems
研究了由葫芦[7]脲(CB[7])和一种光致伸缩性肉桂酰胺衍生物(反式-(3-苯基-丙烯酰氨基)-乙酸,E-1)组成的新型光开关 "开关 "主-客系统。肉桂酰胺衍生物和 CB[7] 形成了稳定的 1:1 主-客复合物(CB[7]-E-1),具有很高的结合常数(K = 2.1 × 104 M-1)。紫外光(300 纳米)照射 CB[7]-E-1 的水溶液会诱导肉桂酰胺衍生物发生从 E 到 Z 的构象变化,然后导致复合物解离,紫外-可见光谱和 1H-NMR 光谱证明了这一点。通过 254 纳米的紫外光照射,CB[7] 和 Z-1 之间形成了光诱导主客复合物的相反过程。这种光开关式 "开-关 "主-客系统显示出很高的可逆性和开关效率,因此可用于设计光致门控系统。