Related Experiment Video
Updated: Aug 17, 2026

Sequence-specific and Selective Recognition of Double-stranded RNAs over Single-stranded RNAs by Chemically Modified Peptide Nucleic Acids
Published on: September 21, 2017
Are conical intersections responsible for the ultrafast processes of adenine, protonated adenine, and the
Steen Brøndsted Nielsen1, Theis I Sølling
1Department of Physics and Astronomy, University of Aarhus, 8000 Aarhus C, Denmark.
Abstract:
Excited-state potential energy surfaces of adenine, protonated adenine, and their N9-methylated analogs are explored by means of a complete active space (CAS) and time-dependent density functional theory (TD-DFT) study to understand the dynamics associated with internal conversion. After photoexcitation of the ground-state molecules to the S(1) state, the nuclear motions that are responsible for taking the wavepacket out of the Franck-Condon region are either an H--N9/C--N9 stretch or a ring-puckering motion that leads to pyramidalization. These motions lead to accessible conical intersections with the ground-state surface. The results are used to successfully interpret previous measurements on the photodissociation of adenosine 5'-monophosphate nucleotide anions and cations, where the latter react in a highly nonstatistical manner.
More Related Videos
Related Concept Videos
Biosynthesis of Nucleic Acids
DNA Base Pairing
Proofreading
Proofreading
Errors During Replication are Corrected by the DNA Polymerase Enzyme
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution

