Interplay of Anion‐π<sup><i>+</i></sup> and π<sup><i>+</i></sup>‐π<sup><i>+</i></sup> Interactions in Novel Pyrido[2,1‐<i>a</i>]isoquinolinium‐Based AIEgens ‐ Substituent‐ and Counterion‐Dependent Fluorescence Modulation and Applications in Live Cell Mitochondrial Imaging**
Ravindra D. Mule, Rupam Roy, Koushik Mandal, Deepak Chopra, Tanoy Dutta, Shashank P. Sancheti, Popat S. Shinde, Somsuvra Banerjee, Apurba Lal Koner, Rohit Bhowal, Beeran Senthilkumar, Nitin T. Patil
Abstract
Abstract Recently, the concept of anion‐π + interactions has witnessed unique applications in the field of AIEgen development. In this contribution, we disclose a consolidated study of a library of N‐doped ionic AIEgens accessed through silver‐mediated cyclization of pyridino‐alkynes. A thorough photophysical, computational and crystallographic study has been conducted to rationalize the observed substituent‐ and counterion‐dependent fluorescence properties of these luminogens. We further elucidate the prominent role of anion‐π + interactions, π + ‐π + interactions and other non‐covalent interactions, in inhibiting the undesired ACQ effect. Finally, we have also demonstrated the application of selected AIEgens for imaging of mitochondria in live cells.