A new benzothiazolium-based organic nonlinear optical material DABT

Second-order nonlinear optical (NLO) crystal materials are applied widely. In this work, a new benzothiazolium-based ionic organic NLO material (E)-2-(4-(dimethylamino)styryl)-3-methylbenzo[d]thiazol-3-ium 4-methylbenzenesulfonate (DABT) containing strong electron donor and acceptor was designed and theoretically investigated. A simple approach that can be employed in rapidly and efficiently evaluating the second-order nonlinear properties of organic crystals based on its crystal structure information was also proposed. Results indicate that the as-designed DABT crystal possesses non-centrosymmetric structure with space group P21, and particularly, it exhibits a large static first-order hyperpolarizability of ∼117 × 10−30 esu. Moreover, the optical properties of the DABT, including its permittivity, absorption coefficient, and reflectance, were systematically investigated, revealing that the DABT crystal is an anisotropic and a new and promising material with hydrophobicity and anisotropy, holding great potential applications in nonlinear optics.