Phenothiazine based co-crystals with enhanced luminescence. (April 2020)

• Record Type: Journal Article
• Authors: Marin, Luminita; Bejan, Andrei; Shova, Sergiu
• Is Part Of: Dyes and pigments. Volume 175(2020)
• Publication Date: 2020-04
• Subjects: Phenothiazine -- Co-crystals -- Halogen bonds -- Quantum efficiency -- Miscibility; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2019.108164
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: A series of binary phenothiazine based co-crystals were designed with the aim to reach materials with improved quantum efficiency in solid state. To this end, a host dibromine functionalized phenothiazine was mixed with a guest formyl based phenothiazine in various molar ratios, from 1:1 up to 1:9, to form single crystals and thin films as well. Single crystal X-ray diffraction, polarized light microscopy, 1 H NMR and FTIR spectroscopies indicated the successful formation of supramolecular synthons via halogen bonds. Polarized light microscopy and atomic force microscopy indicated the formation of submicrometric crystals into the co-crystal films. The photophysical behaviour was investigated by UV–vis and photoluminescence spectroscopies, and showed a remarkable improvement of the quantum yield, reaching values of 27% for single co-crystals and of 42% for thin films of nano-co-crystals. Graphical abstract: Image 1 Highlights: Co-crystals were prepared from isostructural phenothiazine derivatives. Halogen bonds were evidenced as driving forces of co-crystalization. The quantum efficiency increased from 2% to 27% for single co-crystals and of 42% for thin films of nano co-crystals.