A new zinc phthalocyanine–zinc porphyrin dyad (ZnPc–ZnP) fused through a pyrazine ring has been synthesized as a receptor for imidazole-substituted C₆₀ (C₆₀Im) electron acceptor. Self-assembly via metal–ligand axial coordination and the pertinent association constants in solution were determined by ¹H-NMR, UV-Vis and fluorescence titration experiments at room temperature. The designed host was able to bind up to two C₆₀Im electron acceptor guest molecules to yield C₆₀Im:ZnPc–ZnP:ImC₆₀ donor–acceptor supramolecular complex. The spectral data showed that the two binding sites behave independently with binding constants similar in magnitude. Steady-state fluorescence studies were indicative of an efficient singlet–singlet energy transfer from zinc porphyrin to zinc phthalocyanine within the fused dyad. Accordingly, the transient absorption studies covering a wide timescale of femto-to-milli seconds revealed ultrafast energy transfer from ¹ZnP* to ZnPc (k_EnT ∼ 10¹² s⁻¹) in the fused dyad. Further, a photo induced electron transfer was observed in the supramolecularly assembled C₆₀Im:ZnPc–ZnP:ImC₆₀ donor–acceptor complex leading to charge separated states, which persisted for about 200 ns.

中文翻译：

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由两个咪唑-C ₆₀单元组装而成的稠合酞菁锌-卟啉锌双分子的超分子复合物：超快光事件†

已经合成了通过吡嗪环稠合的新型酞菁锌-卟啉锌二联体（ZnPc-ZnP）作为咪唑取代的C ₆₀（C ₆₀ Im）电子受体的受体。在室温下，通过¹ H-NMR，UV-Vis和荧光滴定实验确定了通过金属-配体轴向配位的自组装以及溶液中的相关缔合常数。设计的宿主能够结合多达两个C ₆₀ Im电子受体客体分子，从而产生C ₆₀ Im：ZnPc–ZnP：ImC ₆₀供体-受体超分子复合体。光谱数据表明，两个结合位点的行为独立，且结合常数的大小相似。稳态荧光研究表明，在熔融二聚体中，单峰-单峰能量从卟啉锌转移到酞菁锌中。因此，覆盖的毫微微到毫秒的时间刻度宽的瞬态吸收的研究显示超快能量转移从¹ ZNP *到的ZnPc（ķ _ENT〜10个¹²小号^-1在稠合二分体）。此外，在超分子组装的C ₆₀ Im：ZnPc–ZnP：ImC _60中观察到了光诱导的电子转移。 供体-受体复合体导致电荷分离状态，持续约200 ns。