The electronic and photophysical properties for a series of ruthenium(II) polypyridyl dyes are presented where a π‐accepting 5‐(vinyl‐cyanine)‐8‐oxyquinolate class of ligand is incorporated to yield an improved vis–NIR absorption. A… Click to show full abstract
The electronic and photophysical properties for a series of ruthenium(II) polypyridyl dyes are presented where a π‐accepting 5‐(vinyl‐cyanine)‐8‐oxyquinolate class of ligand is incorporated to yield an improved vis–NIR absorption. A combination of computational, UV–vis–NIR absorption, phosphorescence emission and cyclic voltammetry studies are used to probe the influence of these ligands on complex electronic and photophysical properties. To assess their potential as vis–NIR photoacoustic contrast agents, select complexes were formulated in a PBS buffer/Tween® 20 solvent system. The p‐quinolin‐1‐ium, 1,3,3‐trimethyl‐3H‐indol‐1‐ium and 1,1,3‐trimethyl‐1H‐benzo[e]indol‐3‐ium acceptor groups each impart a strong 680 nm optical absorption and photoacoustic emission on par with the performance exhibited by both the methylene blue and cryptocyanine commercial dyes.
               
Click one of the above tabs to view related content.