Pyrrole hemithioindigo-derived organoboron complexes: Synthesis, photophysical properties and its bioimaging applications

Abstract

The successful synthesis of organoboron complexes with novel core structures facilitates the development of new functional dyes. In this context, synthesizing stable seven-membered organoboron complexes poses substantial challenges, so dyes of this type have seldom been studied. The successful synthesis of a series of pyrrole hemithioindigo-derived organoboron complexes is reported. The photophysical properties have been analyzed, and the results have been compared to those predicted by rigorous theoretical calculations. The presence of a seven-membered ring N,O boron-chelated moiety in these complexes was definitively confirmed by single crystal X-ray diffraction studies. Confocal laser experiments demonstrated the ability of one of the complexes studied to effectively permeate HeLa cells and selectively stain the cytoplasmic region. The reported synthetic strategy provides a framework for synthesizing a wide range of versatile organoboron dyes and opening up new avenues for developing innovative materials.