Okamoto Ken, Fukuzumi Shunichi
Department of Material and Life Science, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency, Suita, Osaka 565-0871, Japan.
J Phys Chem B. 2005 Apr 28;109(16):7713-23. doi: 10.1021/jp050352y.
A series of zinc porphyrin-quinone linked dyads [ZnP-CONH-Q, ZnP-NHCO-Q, and ZnP-n-Q (n = 3, 6, 10)] were designed and synthesized to investigate the effects of hydrogen bonds which can not only provide a structural scaffold to assemble donor and acceptor moieties but also control the photoinduced electron-transfer process. In the case of ZnP-CONH-Q and ZnP-NHCO-Q, the hydrogen bond between the N-H proton and the carbonyl oxygen of Q results in the change in the reduction potential of Q. The strong hydrogen bond between the N-H proton and the carbonyl oxygen of Q*- in ZnP-CONH-Q*-,ZnP-NHCO-Q*-, and ZnP-n-Q*- (n = 3, 6, 10) generated by the chemical reduction has been confirmed by the ESR spectra, which exhibit hyperfine coupling constants in agreement those predicted by the density functional calculations. In the case of ZnP-n-Q (n = 3, 6, 10), on the other hand, the hydrogen bond between two amide groups provides a structural scaffold to assemble the donor (ZnP) and the acceptor (Q) moiety together with the hydrogen bond between the N-H proton and the carbonyl oxygen of Q, leading to attainment of the charge-separated state with a long lifetime up to a microsecond.
设计并合成了一系列锌卟啉-醌连接的二元化合物[ZnP-CONH-Q、ZnP-NHCO-Q和ZnP-n-Q（n = 3、6、10）]，以研究氢键的作用，氢键不仅可以提供一个结构支架来组装供体和受体部分，还可以控制光诱导电子转移过程。在ZnP-CONH-Q和ZnP-NHCO-Q的情况下，N-H质子与Q的羰基氧之间的氢键导致Q的还原电位发生变化。通过化学还原在ZnP-CONH-Q* -、ZnP-NHCO-Q* -和ZnP-n-Q* -（n = 3、6、10）中产生的N-H质子与Q*的羰基氧之间的强氢键已通过电子顺磁共振光谱得到证实，该光谱显示的超精细耦合常数与密度泛函计算预测的一致。另一方面，在ZnP-n-Q（n = 3、6、10）的情况下，两个酰胺基团之间的氢键提供了一个结构支架，将供体（ZnP）和受体（Q）部分组装在一起，同时N-H质子与Q的羰基氧之间也存在氢键，从而导致获得寿命长达微秒的电荷分离态。
