@article{article_1131487, title={Ab-initio Study on Structural, Spectroscopic, and Electronic Properties of (E)-1-(4-Methoxyanthracen-1-yl)-2-phenyldiazene Azo dyes Molecule}, journal={Journal of Spectroscopy and Molecular Sciences}, volume={4}, pages={193–208}, year={2022}, author={Ayun, Arini Qurrata and Tasli, Pinar and Özdemir Kart, Sevgi}, keywords={DFT, UV spektrum, kimyasal kaymalar, elektronik özelliklek, azo boyalar}, abstract={(E)-1-(4-Methoxyanthracen-1-yl)-2-phenyldiazene or C_21 H_16 N_2 O is one of the tautomer azo dyes which is the most usable compound in several industries as a sensing molecule, nowadays. As we know, more than 90% of the existing commercial azo dyes are tautomeric ones (Kelemen, 1981). Quantum chemistry calculations can clarify the relationship between structures and electrochemical properties of molecular compounds for future applications. A comparison of the experimental and theoretical calculations can be very useful in making correct assignments and understanding the relationship between molecular structures and their properties. In this study, the main purpose is to characterize the structural geometries of the title molecule ((E)-1-(4-Methoxyanthracen-1-yl)-2-phenyldiazene), spectroscopic and electronic properties by utilizing ab-initio method based on density functional theory (DFT) (Becke, 1988; Becke, 1993). The molecular geometry and vibrational spectroscopy of the title molecule, in the ground state, have been computed by applying DFT/B3LYP method with the basis set of 6-311G (d,p). The structural properties, such as bond length, bond angle, and dihedral angle, are in excellent agreement with those of available experiment data (Crochet et al., 2011). 114 vibrational modes of the title molecule have been specified with stretching, in-plane-bending, out-of-plane-bending, and torsion vibrations. UV absorption spectra within dimethyl sulfoxide (DMSO) solvent have been predicted by using the time-dependent density functional theory (TD-DFT) (Ronca et al., 2014). Moreover, 1H and 13C NMR chemical shifts have been computed in DMSO solvent by using the Gauge-Invariant Atomic Orbital (GIAO) approach within DFT/B3LYP method (Scott and Radon, 1996; Wolinskiet et al., 1997). Finally, the electronic properties of the title molecule have been also attained by using Koopman’s theorem enable to determine the Lowest Unoccupied Molecular Orbital - Highest Occupied Molecular Orbital (HOMO-LUMO) interaction (Sastri and Perumareddi, 1997; Pearson, 1986). It can be reported that this molecule has gap energy (Eg) bigger than 1.5 eV which indicates thermodynamically stable and durable, low ionization potential energy (IP) which tends to be reducing agents because it is easily losing its electron, about 2.43 eV electron affinity (EA) which denotes that it has good conductive properties, high electronegativity (x) which shows that the title molecule is a polar character, low value of chemical hardness (ƞ) and global electrophilicity index.}, number={2}, publisher={Ozan ÜNSALAN}, organization={Pamukkale University}