Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, USA.
J Phys Chem A. 2011 Mar 24;115(11):2184-95. doi: 10.1021/jp111431r. Epub 2011 Mar 1.
We report recent results on the nonradiative decay (NRD) of fluoren-9-ylidene malononitrile (FM) ambipolar derivatives (FMDs). 2,7- and 3,6-disubstituted FMDs present distinctive photophysics. Charge separation was found dominant for excited state relaxation. The radiative decay (RD) is sensitive to changes in temperature and solvent medium only for the case of 3,6-FMDs. Excited state deactivation of carbazole-containing 3,6-FMD (CPAFM36) was exclusively nonradiative in polar solvents with excited state lifetimes shorter than 10 ps. The charge separation/recombination mechanism of the corresponding FMDs is suggested to fall in the inverted Marcus region of electron transfer. Given the electron-withdrawing properties of the FM unit, its ambipolar derivatives are suggested as potential candidates for air-stable organic thin-film transistors and molecular organic photovoltaics.
我们报告了芴基亚甲基丙二腈（FM）双极性衍生物（FMD）的非辐射衰减（NRD）的最新结果。2,7-和 3,6-取代的 FMD 呈现出独特的光物理性质。电荷分离被发现是激发态弛豫的主要方式。对于 3,6-FMD 的情况，辐射衰减（RD）仅对温度和溶剂介质的变化敏感。含有咔唑的 3,6-FMD（CPAFM36）在极性溶剂中，激发态寿命短于 10 ps，其激发态失活是完全非辐射的。相应的 FMD 的电荷分离/复合机制被认为属于电子转移的倒 Marcus 区域。鉴于 FM 单元的吸电子性质，其双极性衍生物被认为是空气稳定的有机薄膜晶体管和分子有机光伏器件的潜在候选材料。
