In this study, we designed and synthesized novel 6-(thiophen-2-yl) indolizino[3,2-c]quinolines (IQs) guided by density functional theory (DFT) calculations and explored the optical properties of the IQ derivatives together with fractional atomic orbital contribution (FAOC) analysis. In accordance with the DFT predictions, the designed compound, IQ-C9, with a methoxycarbonyl (MC) group attached to the C9 position of the IQ scaffold, displayed improved fluorescence quantum yields (QY) in solution and in the solid state along with bathochromic shifts compared to previous analogues. TEM images demonstrated that IQ-C9 forms well-defined nanoparticle structures (dimensions: 20×50 nm, aspect ratio: 2.3) in aqueous solution. Confocal images of IQ-C9-treated MCF7 cells revealed colocalization of IQ-C9 with lipid droplets, highly dynamic subunits within cells involved in various metabolic disorders and cancers. Our results demonstrated that the analyses based on the FAOC coefficients and molecular orbital (MO) energy levels can be used as a computational method to predict spectral shifts for fluorophores and to design novel fluorescent probes for tracking dynamic cellular processes.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grants (NRF‐2018R1 A2B2005535 and 2018R1 A4 A1021703) funded by the Korean government (MSIT) to J. Lee. This research was also supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education to H. Hwang (2017R1D1 A3B03028669 and 2020R1I1 A3 A04037513) and to J. H. Lee (2020R1I1 A1 A01073381).
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Organic Chemistry
- Analytical Chemistry