Vibrational and electronic absorption spectroscopic and density functional theoretical studies on the 2(3H)-benzothiazolone and its anion

Abstract

In this paper, 2(3H)-benzothiazolone(2-BTO) was investigated in crystalloid using infrared, and Raman spectroscopies combining with density functional theoretical (DFT) calculation. Further using the steady absorption spectra, the dimer and anion structures were characterized combining with the time-dependent density functional theoretical (TD-DFT) calculations. Our results indicated that in the crystalline the dimer was stabilized due to the strong intermolecular hydrogen bonds (HBs) by vibrational spectroscopic and DFT calculation, and even in methanol and water solvents, the hydrogen bonds between BTO and methanol, even and water could not catch up with the HBs strength of the dimer. However, only was the base doped into methanol and water, hydrogen bonds between the dimer would be cleavage to further produce the monomer anion, which can be determined by the steady UV–Vis absorption spectroscopy and TD-DFT calculation. A simple, convenient and pratical method is proposed to detect the structure and optical properties of benzothiazolones and its anion.