Excited-State Properties and Relaxation Pathways of Selenium-Substituted Guanine Nucleobase in Aqueous Solution and DNA Duplex.

ABSTRACT: The excited-state properties and relaxation mechanisms after light irradiation of 6-selenoguanine (6SeG) in water and in DNA have been investigated using a quantum mechanics/molecular mechanics (QM/MM) approach with the multistate complete active space second-order perturbation theory (MS-CASPT2) method. In both environments, the S₁ ¹(n_Seπ₅^*) and S₂ ¹(π_Seπ₅^*) states are predicted to be the spectroscopically dark and bright states, respectively. Two triplet states, T₁ ³(π_Seπ₅^*) and T₂ ³(n_Seπ₅^*), are found energetically below the S₂ state. Extending the QM region t

SUBMITTER: Fang YG 

PROVIDER: S-EPMC8023715 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature