Aggregation induced emission-active molecules bearing tunable singlet oxygen generation: The different length alkyl chain matters.

The efficiency of singlet oxygen (O) can be subtly regulated by molecular alkyl chain length according to ΔE (the energy gap between S and T states). Which offer a strategy to adjust the O yield of photosensitizers (PSs) by molecular design strategy. Herein, three PSs (MZ1 ~ MZ3) were constructed of β-terpyridine derivatives, which possess different length alkyl chain (butyl, hexyl, and octyl group) with tunable O yield (3.366, 2.461 and 0.963). Based on studies that PSs with aggregation induced emission (AIE) characteristics showed effective emission intensity and high O yield. Subsequently, Photodynamic therapy (PDT) in vitro was further investigated. MZ1 showed relatively highest O yield, considerable cellular uptake and effective cell apoptosis upon light irradiation.