A LIGHT-INDUCED MOLECULAR SHUTTLE BASED ON A [2]ROTAXANE-DERIVED TRIAD
A LIGHT-INDUCED MOLECULAR SHUTTLE BASED ON A [2]ROTAXANE-DERIVED TRIAD
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DOI：
10.1002/anie.199314591
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发表时间：
1993-10-01
期刊：
影响因子：
--
通讯作者：
HARRIMAN, A
中科院分区：
文献类型：
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作者：
BENNISTON, AC;HARRIMAN, A
Fig. 1.激光激发[2]轮烷3在乙腈溶液中后，记录了a）5 ps和B）200 ps的瞬时差分吸收光谱。每个光谱的插图显示了在410 nm处记录的衰减曲线及其计算的最佳拟合。电荷转移复合物的范围。相同的吸收光谱特征出现以下的[2]轮烷的激光激发的末端二茂铁亚基取代三异丙基甲硅烷基。然而，对于后一个系统观察到的瞬态吸收信号完全衰减到预脉冲基线，寿命约为9 ps，而对于3观察到的瞬态吸收信号衰减到约22 ps的寿命，留下残留信号（图1a）。用30 ps激光脉冲在532 nm激发后记录的较长寿命物质的瞬态吸收光谱（图1 B）与激发3后立即观察到的光谱非常相似（如果不相同的话），并且该物质通过一级动力学缓慢衰减，寿命为550 ns（图1 B）。在与上述条件相同的条件下激发轮烷而不激发环蕃（即化合物1），不会产生任何可检测的瞬态物质。
Fig. 1. Transient differential absorption spectra recorded a) 5 ps and b) 200 ps after laser excitation of the [2] rotaxane 3 in acetonitrile solution. The insert to each spectrum shows the decay profile recorded at 410 nm together with its computed best fit. confines of a charge-transfer complex. The same absorption spectral features appear following laser excitation of the [2] rotaxane having the terminal ferrocene subunits replaced with triisopropylsilyl groups. However, whereas the transient absorption signal observed for this latter system decayed completely to the prepulse baseline with a lifetime of about 9 ps, that observed for 3 decayed with a lifetime of about 22 ps to leave a residual signal (Fig. 1 a). The transient absorption spectrum of the longer lived species, as recorded following excitation at 532nm with a 30ps laser pulse (Fig. 1 b), was very similar, if not identical, to that observed immediately after excitation of 3, and the species decayed slowly by first-order kinetics with a lifetime of 550 ns (Fig. 1 b). Excitation of the rotaxane without the cyclophane (ie, compound 1) under conditions identical to those described above did not give rise to any detectable transient species.