Photoinduced charge separation of phenothiazine–platinum–naphthalene diimide triads linked by twisted phenylene bridges
作者:Ryoji Sugimura、Shuichi Suzuki、Masatoshi Kozaki、Kazutoshi Keyaki、Koichi Nozaki、Hironori Matsushita、Noriaki Ikeda、Keiji Okada
DOI:10.1007/s11164-012-0642-6
日期:2013.1
Two triads (i.e., 3PTZ–Pt–MNDI and 10PTZ–Pt–MNDI) consisting of 3-phenothiazine (3PTZ) or 10-phenothiazine (10PTZ), bipyridine–diacetylide platinum complex (Pt), and naphthalene diimide (MNDI) chromophores linked by highly twisted biphenylene spacers have been prepared. The formation and decay of the charge-separated (CS) states in toluene were studied by use of picosecond and nanosecond laser photolysis via selective excitation of the Pt moiety. The time required for formation of the CS state, PTZ+–Pt–MNDI−, from PTZ–3Pt*–MNDI was determined to be τ CS = 280 ps for 3PTZ+–Pt–MNDI− and τ CS = 230 ps for 10PTZ+–Pt–MNDI−. The lifetimes of the CS states were determined to be τ CR1 = 75 ns (95 %) and τ CR2 = 285 ns (5 %) for 3PTZ+–Pt–MNDI− and τ CR = 830 ns for 10PTZ+–Pt–MNDI−. Formation and decay of the CS states are discussed in terms the Marcus theory and the spin-correlated radical pair mechanism.
我们制备了两种三元组(即 3PTZ-Pt-MNDI 和 10PTZ-Pt-MNDI ),它们由 3-吩噻嗪(3PTZ)或 10-吩噻嗪(10PTZ)、联吡啶二乙酰铂络合物(Pt)和萘二亚胺(MNDI)发色团组成,并通过高度扭曲的联苯间隔相连。通过选择性激发铂分子,利用皮秒和纳秒激光进行光解,研究了甲苯中电荷分离(CS)态的形成和衰减。经测定,由 PTZ-3Pt*-MNDI 形成 CS 态 PTZ+-Pt-MNDI- 所需的时间为:3PTZ+-Pt-MNDI- τ CS = 280 ps 和 10PTZ+-Pt-MNDI- τ CS = 230 ps。经测定,3PTZ+-Pt-MNDI- 的 CS 状态寿命为 τ CR1 = 75 ns (95 %) 和 τ CR2 = 285 ns (5 %),10PTZ+-Pt-MNDI- 的 CS 状态寿命为 τ CR = 830 ns 。根据马库斯理论和自旋相关自由基对机制讨论了 CS 状态的形成和衰变。