Tunable Properties of New Cyano‐Substituent Heptahelicenes for Optoelectronic Devices: A Combined Experimental and DFT Computational Study

Abstract

Here, we describe a set of coupled experimental and theoretical analyses. The introduction of one and two additional cyano groups in the carboheptahelicene backbone enhance its electron‐accepting properties. New carboheptahelicene derivatives are synthesized, and relevant characterizations of structural features, photophysical and electrochemical properties, and structure‐property relationships are described. This present work concerns the use of the density functional theory (DFT) to highlight the structural and the optoelectronic properties of carboheptahelicene derivatives and comparing the obtained findings with the experimental ones. The experimental and theoretical spectra (UV‐Vis absorption and photoluminescence) provide excellent concurrence. Afterward, molecular structures, structural parameters, molecular electrostatic potential (MEP), highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies of frontier molecular orbitals (FMOs) are constructed. Some other optoelectronic parameter including electron affinity (EA), ionization potential (IP), and some reactive descriptor such as chemical potential (μ), global hardness (η), electronegativity (χ) and the overall electrophilicity index (ω) are determined and indicating its potential uses as an active layer in optoelectronic efficient devices. The topological methods such as electron localization function (ELF), localization orbital locator (LOL) and the reduced density gradient method (RDG) were also conducted to clarify the strengths and kinds of interactions.