Water-soluble chiral tetrazine derivatives: towards the application of circularly polarized luminescence from upper-excited states to photodynamic therapy.

ABSTRACT: A new family of water-soluble chiral tetrazine derivatives 1 and 2 is reported. Spectroscopic studies reveal that the derivatives violate Kasha's rule and emit from their upper-excited states (S _n , n > 1). The transition assignments are supported by time-dependent density functional theory calculations. More importantly, both chromophores exhibit anisotropy factors on the order of ?10^-3 to 10^-4 for circular dichroism and circularly polarized luminescence (CPL) from upper-excited states. Additionally, the nonplanar geometry of the derivatives induces a significant yield of triplet excited states. Transient absorption spectroscopic measurements reveal high triplet quantum yields of ?86% for 1 and ?81% for 2. Through in vitro studies, we demonstrate that the derivatives can be used as photodynamic therapy (PDT) agents, providing a highly efficient form of cancer therapy. This study is the first demonstration of simple organic molecules with CPL from upper-excited states and efficient PDT.

SUBMITTER: He T 

PROVIDER: S-EPMC6471655 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature