New fluorescent switches based on photochromic 2,3-diarylcyclopent-2-en-1-ones and 6-ethoxy-3-methyl-1H-phenalen-1-one

New fluorescent switches with 2,3-diarylcyclopent-2-en-1-ones as the photochromic component and 6-ethoxy-3-methyl-1H-phenalen-1-one as the fluorophore have been prepared. Two approaches to develop the photoswitches have been applied. The first involves covalent binding of the fluorophore to photochromic diarylethene molecule by ether linkage. The second type of fluorescent switch was been prepared by the blending of the photochromic 2,3-diarylcyclopent-2-en-1-ones and 6-ethoxy-3-methyl-1H-phenalen-1-one in various ratios. The spectral properties of fluorescent switches have been investigated and possible ways of fluorescence quenching are discussed.

► Synthesis of two types fluorescent switches based on 2,3-diarylcyclopent-2-en-1-ones.
► The first involves covalent binding of the fluorophore to the photochromic molecule.
► The second photoswitches include the blending of photochromic and fluorescent units.
► The spectral properties and fluorescence quenching of photoswitches were studied.
► It was found that covalent binding photoswitches are most preferred than the blends.