Heavy-atom-free orthogonal configurative dye 1,7-di-anthra-aza-BODIPY for singlet oxygen generation

Spin-orbit,charge-transfer intersystem crossing （SOCT-ISC） can directly overcome the disadvantages of the traditional heavy-atom effect and improve the generation efficiency of reactive oxygen species （ROS）.Since orthogonal molecular orbitals of donor-acceptor （D-A） pairs favor the SOCT-ISC transition,herein aza-borondipyrromethenes （aza-BODIPYs） with 1,7-di-anthracyl groups （An-azaBDP） was successfully prepared,owing to steric hindrance to produce a big dihedral angle between the two molecular orbital （MO）planes.Moreover,according to density functional theory （DFT） and time-dependent density functional theory （TDDFT）,the energy difference between the S1-T1orbitals of An-aza BDP is small and more inclined towards ISC.An-aza BDP can effectively generate singlet oxygen under light irradiation.An-aza BDP with light irradiation can induce apoptosis in SW620 cells,and can serve as a potential candidate for the treatment of cancer cells and tumors.