Photophysical Tuning of Shortwave Infrared Flavylium Heptamethine Dyes via Substituent Placement
Monica Pengshung, Jingbai Li, Fatemah Mukadum, Steven A. Lopez, Ellen M. Sletten
Abstract
Optical imaging in the shortwave infrared region (SWIR, 1000–2000 nm) provides high-resolution images in complex systems. Here we explore substituent placement on dimethylamino flavylium polymethine dyes, a class of SWIR fluorophores. We find that the position of the substituent significantly affects the λmax and fluorescence quantum yield. Quantum-mechanical calculations suggest that steric clashes control the extent of π-conjugation. These insights provide design principles for the development of fluorophores for enhanced SWIR imaging.
Topics & Concepts
ChemistrySubstituentShortwavePhotochemistryInfraredOptoelectronicsOrganic chemistryOpticsRadiative transferPhysicsGold and Silver Nanoparticles Synthesis and ApplicationsPhotochromic and Fluorescence ChemistryPhotoreceptor and optogenetics research