Experimental and Computational Studies of the Neutral and Reduced States of Indeno[1,2‑b]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.