A naphthalimide fluorophore with efficient intramolecular PET and ICT Processes: Application in molecular logic
作者:Haixia Wang、Haixia Wu、Lin Xue、Yan Shi、Xiyou Li
DOI:10.1039/c1ob05481c
日期:——
A novel 4-amino-1,8-naphthalimide (NDI) with two different metal cation receptors connected at 4-amino or imide nitrogen positions respectively was designed and prepared. Significant internal charge transfer (ICT) as well as photoinduced electron transfer (PET) from the receptors to NDI is revealed by the shifted UV-vis absorption spectra and significant fluorescence quenching. Both Zn2+ and Cu2+ can coordinate selectively with the two cation receptors in this molecule with different affinities. The coordination of Zn2+ with the receptor at imide nitrogen hindered the PET process and accordingly restored the quenched fluorescence of NDI. But the coordination of Zn2+ at 4-amino position blocked the ICT process and caused significant blue-shift on the absorption peak with the fluorescence intensity unaffected. Similarly, coordination of Cu2+ with the receptor at imide nitrogen can block the PET process, but can not restore the quenched fluorescence of compound 3 due to the paramagnetic properties of Cu2+, which quench the fluorescence significantly instead. With Cu2+ and Zn2+ as two chemical inputs and absorption or fluorescence as output, several logic gate operations, such as OR, NOR and INHIBIT, can be achieved.
设计并制备了一种新型的4-氨基-1,8-萘二酰亚胺(NDI),其具有两个分别连接在4-氨基或酰亚胺氮位的不同金属阳离子受体。通过紫外可见吸收光谱的偏移和显著的荧光淬灭,揭示了从受体到NDI的显著内部电荷转移(ICT)以及光诱导电子转移(PET)。Zn²⁺和Cu²⁺均可与该分子中的两个阳离子受体选择性配位,但其亲和力不同。Zn²⁺与酰亚胺氮位的受体配位抑制了PET过程,从而恢复了NDI的荧光淬灭。然而,Zn²⁺在4-氨基位置的配位阻碍了ICT过程,并导致吸收峰显著蓝移,而荧光强度未受影响。同样,Cu²⁺与酰亚胺氮位的受体配位可以阻止PET过程,但由于Cu²⁺的顺磁特性,无法恢复化合物3的淬灭荧光,反而显著淬灭荧光。以Cu²⁺和Zn²⁺作为两种化学输入,以吸收或荧光作为输出,可以实现多种逻辑门操作,如OR、NOR和抑制(INHIBIT)。