Open AccessPhotophysical Tuning of Shortwave Infrared Flavylium Heptamethine Dyes via Substituent Placement
Author(s) -
Monica Pengshung,
Jingbai Li,
Fatemah Mukadum,
Steven Lopez,
Ellen M. Sletten
Publication year - 2020
Publication title -
organic letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.94
H-Index - 239
eISSN - 1523-7060
pISSN - 1523-7052
DOI - 10.1021/acs.orglett.0c02213
Subject(s) - substituent , chemistry , photochemistry , quantum yield , steric effects , fluorescence , shortwave , infrared , yield (engineering) , organic chemistry , optics , materials science , radiative transfer , physics , metallurgy
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 λ max 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.