Experimental and Computational Studies of the Neutral and Reduced States of Indeno[1,2‑<i>b</i>]fluorene

This study examines the intrinsic structural and optoelectronic properties of the neutral indeno­[1,2-b]­fluorene skeleton as well as those of the corresponding anion radical and dianion. We report their characterization by analysis of solid-state structures and EPR, NMR, and absorbance spectra. Additionally, 20 popular density functional theory methods are used to evaluate their performance for predicting NMR chemical shifts, EPR hyperfine coupling constants, and low-energy transitions of the absorbance spectrum to act as a guide for future studies. This information can be used for a better understanding and tuning of the electron-transporting/accepting ability of the indeno­fluorene core for use in organic photovoltaics and organic field effect transistors.本研究考察了中性茚并[1,2-b]芴（indeno[1,2-b]fluorene）骨架的本征结构与光电性质，以及其对应的阴离子自由基和二阴离子的相关性质。我们通过固态结构分析、电子顺磁共振（EPR）、核磁共振（NMR）以及吸收光谱对其进行了表征。此外，本研究采用20种主流密度泛函理论方法，评估其在预测NMR化学位移、EPR超精细耦合常数以及吸收光谱低能跃迁方面的性能，为后续相关研究提供参考。该研究结果可用于更深入地理解并调控茚并芴核的电子传输/接受能力，以应用于有机光伏与有机场效应晶体管领域。