Namely, the chelates displayed fluorescence emissive properties with fluorescence quantum yields in the range of 0.01-0.07 in toluene; whereas in ethanol the signal was negligible. Chelates 13b, 13h, 13i and 13j displayed the higher yields in toluene. A similar trend was observed in the singlet excited state lifetimes ranging from 1.5 -5 ns. Consequently, because of the CT states, AL(DIPY)3 efficiently populate triplet excited states with long-lived triplet state lifetimes in air-equilibrated conditions (250-350 ns). Complexes 13d, 13h, 13i and 13j displayed the highest triplet state lifetimes in toluene and 13c, 13h and 13i in ethanol. Additionally, in the absence of oxygen, the triplet state lifetimes ascend up to the range of 50-200 µs, confirming that the complexes' reactivity with oxygen is of paramount importance after photoexcitation. Next, comparing the singlet oxygen formation in ethanol and toluene, we can conclude that in the polar solvent, luminescence is apparent but not significantly detected, while toluene proved more suitable for the measurements. Complexes 13d, 13f, 13h, 13i and 13j showed high singlet oxygen generation in both solvents. Preliminary results of the in vitro screening of eight AL(DIPY)3 against CT26 cells are promising, as these complexes were able to trigger cell death upon irradiation at safe nanomolar and micromolar concentrations. Specifically, we identified possible PS candidates since four of the complexes induced phototoxicity with the following ascending order: 13d < 16 < 17 < 13h, pointing to the latter as the best PS candidate. Complexes with polar groups attached might express improved amphiphilicity, allowing for a better cell internalization and permeability and thus exerting their phototoxic efficiency. To summarize, we conducted a comprehensive study on the development of novel homoleptic tris(dipyrrinato)metal(III) complexes with aluminum as earthabundant element. Together with the low toxicity, the investigation of their photophysical properties and their first screening of photocytotoxicity points towards possible uses as photosensitizers in medicinal bioinorganic chemistry.