Ultrasound-assisted synthesis, photophysical behaviour and single crystal X-ray analysis of highly functionalized prenylarenes

• Published in: Journal of molecular structure 2022-05, Vol.1256, p.132544, Article 132544
• Main Authors: Krishnan, Manjula, Singh, Fateh V
• Format: Article
• Language: English
• Subjects: Blue fluorescence; Carbanion-induced; Metal free; Prenylarenes; Twisted phenyl rings; Ultrasound
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2022.132544

•Synthesis of blue fluorescent functionalised prenylarenes in good yields.•The synthesised compounds were characterised by their 1H NMR, 13C NMR, Mass and IR analysis.•The photophysical behaviour of the synthesised compounds was studied by using UV-Vis and fluorescence spectroscopy. A rapid, ultrasound assisted base-catalysed metal free synthesis of a novel series linear prenylarenes 17 incorporated with donor-acceptor functionalities is described via carbanion-induced ring transformation of 4-amino-6-aryl-3-cyano-2H-pyran-2-ones 15 with 6-methylhept-5-en-2-one 16 at room temperature with high yields. Notably, all of the synthesised prenylarenes exhibited blue fluorescence in the 406–468 nm region. The stokes shift, optical band gap, and quantum yield of compounds 17a-17l were computed using their absorption and emission spectra. A significant positive solvatochromic effect was observed, and concentration studies revealed the non-aggregating behaviour of synthesised prenylarenes. Single crystal X-ray diffraction analysis of 17d revealed that crystal belongs to triclinic system with P-1 space group with twisted phenyl rings. [Display omitted] .