Synthesis, structure and mechanofluorochromic properties of phenothiazine-S-oxide and phenothiazine-S,S-dioxide derivatives

Ming-Xing Zhang; Xiaofei Yang; Fen Tan; Hongquan Zhang; Guoping Zeng; Zhiqiang Xu; Sheng Hua Liu

doi:10.1016/j.saa.2023.122427

Synthesis, structure and mechanofluorochromic properties of phenothiazine-S-oxide and phenothiazine-S,S-dioxide derivatives

Spectrochim Acta A Mol Biomol Spectrosc. 2023 May 5:292:122427. doi: 10.1016/j.saa.2023.122427. Epub 2023 Feb 2.

Authors

Ming-Xing Zhang¹, Xiaofei Yang², Fen Tan³, Hongquan Zhang³, Guoping Zeng³, Zhiqiang Xu⁴, Sheng Hua Liu⁵

Affiliations

¹ Hubei Key Laboratory of Purification and Application of Plant Anti-cancer Active Ingredients, College of Chemistry and Life Science, Hubei University of Education, Wuhan 430205, PR China; Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
² Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
³ Hubei Key Laboratory of Purification and Application of Plant Anti-cancer Active Ingredients, College of Chemistry and Life Science, Hubei University of Education, Wuhan 430205, PR China.
⁴ Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, PR China. Electronic address: 19070201@wit.edu.cn.
⁵ Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China. Electronic address: chshliu@mail.ccnu.edu.cn.

PMID: 36764141
DOI: 10.1016/j.saa.2023.122427

Abstract

In this work, two novel luminescent molecules containing distorted phenothiazine-S-oxide and phenothiazine-S,S dioxide skeletons were synthesized by oxidation reactions using different oxidants (m-chloroperoxybenzoic acid, acetic acid /hydrogen peroxide). The target compounds were all confirmed by ¹H NMR, ¹³C NMR and EI-MS. Combined with the results of UV-vis absorption spectra and fluorescence emission spectra, we found that the different oxidation states of S-atom, from sulfide (+2) to sulfoxide (+4) and sulfone (+6), led to the blue, yellow-green and yellowish fluorescence of these compounds in the solid states. Subsequent studies showed that the molecule containing the phenothiazine-S-oxide skeleton exhibited obvious solvatochromism, and the increase of solvent polarity induced a red-shift in the emission wavelength. Moreover, this molecule also exhibited a rare self-recovery mechanochromatic behavior. In addition, these properties were further confirmed by theoretical calculations and X-ray single-crystal diffraction analysis.

Keywords: Mechanochromic; Phenothiazine; Self-recovering; Solvatochromism.