Experimental and theoretical analyses on structural (monomer and dimeric form), spectroscopic and electronic properties of an organic semiconductor 2,6-dimethoxyanthracene

In this work, a promising organic semiconductor 2,6-dimethoxyanthracene (2,6-DA) molecule was widely characterized experimentally through FTIR in the region of 4000–450 cm −1 and FT Raman in the region of 4000–50 cm −1 , respectively. Theoretical calculations were performed by employing Gaussian 09 software using DFT/B3LYP/6-311++G(d,p) method. The barrier potential energy due to internal rotation optimized the structural parameters and vibrational harmonic frequencies. MOLVIB program was used to scale the theoretical frequencies for a better fit with the experimental frequencies; the rms error of 9.4 cm −1 was obtained between the observed and scaled frequencies. Geometric optimization was made for dimer in order to lend theoretical support for the existence of hydrogen bond in 2,6-DA at the same level of theory as used for the monomer. First-order hyperpolarizability, natural bond orbital analysis, molecular electrostatic surface potential and Fukui functions were calculated. Electronic properties like HOMO–LUMO energies, regeneration energy (Δ G reg ), electronic injection energy (Δ G inject ), light-harvesting efficiency were performed in gas phase and in different solvents to determine the shift of higher absorption wavelength, employing time-dependent density functional theory.