Synthesis of a New Nitrile-Based Diamine, NMR Spectra and DFT Studies

Herein, 4-(Bis(4-aminophenyl)amino)-2-chlorobenzonitrile was synthesized in detail by experimental and theoretical methods. Structural confirmation of the compound was carried out by ¹H-NMR and ¹³C-NMR spectroscopy. In order to determine the electronic and optoelectronic properties of the molecule, Density Functional Theory (DFT) and Time Dependent DFT (TD-DFT) calculations were performed at the B3LYP, B3PW91 and CAM-B3LYP/6-31G levels. In the obtained UV-Vis spectrum, two characteristic absorption bands were observed, corresponding to the π→π* transition around 300 nm and the intramolecular charge transfer (ICT) transition specific to the donor-acceptor structure in the range of 480-500 nm. The ECD spectrum showed that these transitions gave optical responses with opposite signs, indicating a weak chiral asymmetry or charge distribution orientation in the molecule. The MEP map confirmed that the nitrile group is an electron acceptor and the amine groups are electron donors, and showed that the molecule exhibits a typical push-pull architecture. The calculated dipole moment values indicated that the molecule has high polarizability, while the polarizability (α ≈ 297–303 a.u.) and hyperpolarizability (β ≈ 1.55×10-34–1.90×10-34esu) values supported the second-order nonlinear optical (NLO) response potential.