Creation of Superheterojunction Polymers via Direct Polycondensation: Segregated and Bicontinuous Donor鈥揂cceptor 蟺-Columnar Arrays in Covalent Organic Frameworks for Long-Lived Charge Separation

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• 作者：Shangbin Jin ; Mustafa Supur ; Matthew Addicoat ; Ko Furukawa ; Long Chen ; Toshikazu Nakamura ; Shunichi Fukuzumi ; Stephan Irle ; Donglin Jiang
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：June 24, 2015
• 年：2015
• 卷：137
• 期：24
• 页码：7817-7827
• 全文大小：801K
• ISSN：1520-5126

文摘

By developing metallophthalocyanines and diimides as electron-donating and -accepting building blocks, herein, we report the construction of new electron donor鈥揳cceptor covalent organic frameworks (COFs) with periodically ordered electron donor and acceptor 蟺-columnar arrays via direct polycondensation reactions. X-ray diffraction measurements in conjunction with structural simulations resolved that the resulting frameworks consist of metallophthalocyanine and diimide columns, which are ordered in a segregated yet bicontinuous manner to form built-in periodic 蟺-arrays. In the frameworks, each metallophthalocyanine donor and diimide acceptor units are exactly linked and interfaced, leading to the generation of superheterojunctions鈥攁 new type of heterojunction machinery, for photoinduced electron transfer and charge separation. We show that this polycondensation method is widely applicable to various metallophthalocyanines and diimides as demonstrated by the combination of copper, nickel, and zinc phthalocyanine donors with pyrommellitic diimide, naphthalene diimide, and perylene diimide acceptors. By using time-resolved transient absorption spectroscopy and electron spin resonance, we demonstrated that the COFs enable long-lived charge separation, whereas the metal species, the class of acceptors, and the local geometry between donor and acceptor units play roles in determining the photochemical dynamics. The results provide insights into photoelectric COFs and demonstrate their enormous potential for charge separation and photoenergy conversions.