Novel near-infrared luminescent compounds based on platinum(II) 4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine-fused chlorins are described. These compounds have high photostability and display light emission, in particular simultaneous fluorescence and phosphorescence emission in solution at room temperature, in the biologically relevant 700-850 nm red and near-infrared (NIR) spectral region, making them excellent ...