Exciton Absorption and Luminescence in i-Motif DNA.

ABSTRACT: We have studied the excited-state dynamics for the i-motif form of cytosine chains (dC)₁₀, using the ultrafast fluorescence up-conversion technique. We have also calculated vertical electronic transition energies and determined the nature of the corresponding excited states in a model tetramer i-motif structure. Quantum chemical calculations of the excitation spectrum of a tetramer i-motif structure predict a significant (0.3 eV) red shift of the lowest-energy transition in the i-motif form relative to its absorption maximum, which agrees with the experimental absorption spectrum. The lowest excitonic state in i-(dC)₁₀ is responsible for a 2 ps red-shifted emission at 370 nm observed in the decay-associated spectra obtained on the femtosecond time-scale. This delocali

SUBMITTER: Reveguk ZV 

PROVIDER: S-EPMC6831829 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature