Development of Pyrene Derivatives as Promising n-Type Semiconductors: Synthesis, Structural and Spectral Properties

A series of promising candidates for n-type semiconductors, which were based on a 1,6-, 1,8- and mono-substituted pyrene-thiophene backbone with a cyano group and dicyanovinylene moieties, were synthesized. The compounds were characterized using NMR spectroscopy, elemental analysis, UV-vis, photoluminescence (PL), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), cyclic voltametry (CV) and DFT calculations. The substituent effects on molecular properties were studied in detail. It was found that the dicyanovinylene substitution enhanced the coplanarity of the -conjugated systems as compared to cyano substitution. The LUMO energy level was located deeply, and one of them had LUMO of below -4.00eV, indicating that they may be promising candidates for n-type semiconductors.