A Concept for Controlling Singlet Oxygen (1g) Yields Using Nitroxide Radicals: Phthalocyaninatosilicon Covalen
详细信息 查看全文
- 作者：Kazuyuki Ishii ; Shoji Takeuchi ; Shinsuke Shimizu ; and Nagao Kobayashi
- 刊名：Journal of the American Chemical Society
- 出版年：2004
- 出版时间：February 25, 2004
- 年：2004
- 卷：126
- 期：7
- 页码：2082 - 2088
- 全文大小：172K
- 年卷期：v.126,no.7(February 25, 2004)
- ISSN：1520-5126
文摘
In this study, we have investigated the singlet oxygen (1
g) generation mechanism usingphthalocyaninatosilicon (SiPc) covalently linked to nitroxide radicals (NRs), and we succeeded in increasingthe singlet oxygen quantum yield (
) by linking the NRs. This originates from both an increase in thetriplet quantum yield and excited-state lifetimes long enough to utilize photochemical reactions. Becausethe electron exchange interactions with paramagnetic species were known to result only in very fast excited-state relaxation, leading to a decrease in photochemical reaction yields, this increase in is an unusualand precious example for increasing photochemical reaction yields by electron exchange interactions withparamagnetic species. In addition, our experiments and theoretical analyses show that the spin-selectiveenergy transfer rate constant is not influenced by linking the NRs and can be evaluated by the product ofspin-statistical factors and matrix elements between the initial and final states.
g) generation mechanism usingphthalocyaninatosilicon (SiPc) covalently linked to nitroxide radicals (NRs), and we succeeded in increasingthe singlet oxygen quantum yield () by linking the NRs. This originates from both an increase in thetriplet quantum yield and excited-state lifetimes long enough to utilize photochemical reactions. Becausethe electron exchange interactions with paramagnetic species were known to result only in very fast excited-state relaxation, leading to a decrease in photochemical reaction yields, this increase in is an unusualand precious example for increasing photochemical reaction yields by electron exchange interactions withparamagnetic species. In addition, our experiments and theoretical analyses show that the spin-selectiveenergy transfer rate constant is not influenced by linking the NRs and can be evaluated by the product ofspin-statistical factors and matrix elements between the initial and final states.