Department of Information and Basic Science, Nagoya City University, Nagoya 467-8501, Japan.
Division of Chemistry, Faculty of Pure and Applied Sciences, and Tsukuba Research Center for Energy Materials Sciences (TREMS), University of Tsukuba, Tsukuba 305-8571, Japan.
J Phys Chem B. 2021 Jan 28;125(3):918-925. doi: 10.1021/acs.jpcb.0c10450. Epub 2021 Jan 14.
Here we report an anionic -tetrakis(4-carboxymethylthio-2,3,5,6-tetrafluorophenyl) zinc porphyrin (ZnTFPPTC) to form a supramolecular complex with a cationic lithium endohedral [60]fullerene (Li@C). The supramolecular ZnTFPPTC/Li@C complex formed by strong electrostatic attraction with a large binding constant generates a long-lived charge-separated (CS) state with low energy loss by photoinduced electron transfer from ZnTFPPTC to Li@C. The anionic fluorinated zinc porphyrin with high oxidation potential reduces the energy loss associated with the charge separation and enhances the energy level of the CS state. The energy level of the CS state determined by electrochemical measurements is at 0.94 eV, which is much higher than that of a similar supramolecular complex using an anionic -tetrakis(sulfonatophenyl) zinc porphyrin (ZnTPPS) at 0.55 eV. Time-resolved transient absorption spectroscopy demonstrates that ZnTFPPTC/Li@C generates a long-lived CS state with a lifetime of 0.29 ms in a binary solvent of acetonitrile and chlorobenzene. The lifetime of the CS state is comparable to that of ZnTPPS/Li@C in benzonitrile.
在这里，我们报告了一种阴离子四（4-羧甲基硫代-2,3,5,6-四氟苯基）锌卟啉（ZnTFPPTC）与阳离子锂内嵌富勒烯（Li@C）形成超分子复合物。通过强静电吸引形成的超分子 ZnTFPPTC/Li@C 复合物具有大的结合常数，通过 ZnTFPPTC 向 Li@C 的光致电子转移产生长寿命的电荷分离（CS）态，能量损失低。具有高氧化电位的阴离子氟化锌卟啉降低了与电荷分离相关的能量损失，并提高了 CS 态的能级。电化学测量确定的 CS 态能级为 0.94 eV，远高于使用阴离子四（磺酸钠苯基）锌卟啉（ZnTPPS）的类似超分子复合物的 0.55 eV。时间分辨瞬态吸收光谱表明，ZnTFPPTC/Li@C 在乙腈和氯苯的二元溶剂中生成具有 0.29 ms 寿命的长寿命 CS 态。CS 态的寿命与苯腈中的 ZnTPPS/Li@C 相当。
