ABSTRACT A series of hemicyanine derivatives was synthesized via condensation of 1,2,3,3‐tetramethyl‐3H‐indolium and its 5‐iodo and 4,6‐diiodo derivatives with polyaromatic aldehydes. Their spectral properties, singlet oxygen photogeneration, and inhibitory activity against vesicular stomatitis virus (VSV) were investigated. The aim of this study was to combine a positive charge for improved solubility with either a pyrene or perylene polycycle and heavy iodine atoms to enhance singlet oxygen generation and induce a bathochromic shift in the dye absorption. It was found that the synthesized hemicyanines are unstable both toward various nucleophiles, particularly the cyanide anion, and toward light. Although the perylene‐based derivatives demonstrate antiviral activity against VSV, the potential application of such compounds lies not in the antiviral domain but rather in the field of chemical sensors and pH indicators.
Krasilnikov et al. (Sun,) studied this question.