Abstract
Steady state spectroscopy, femtosecond transient absorption spectroscopy (fsTA), and femtosecond stimulated Raman spectroscopy (FSRS) of DNA mini-hairpins possessing a diphenylacetylenedicarboxamide (DPA) linker and 1-3 adenine-thymine (A-T) or guanine-cytosine (G-C) base pairs have been investigated. Ultraviolet and circular dichroism (UV and CD) spectra are consistent with ground state conformations that are predominantly base-paired and π-stacked for conjugates possessing two or three base pairs; however, they offer no information concerning the conformation of conjugates possessing a single base pair. fsTA spectra are indicative of π-stacked structures excepted in the case of the conjugate possessing a single G-C base pair. All of the conjugates display transient absorption bands characteristic of the DPA-. anion radical. Conjugates possessing two or three G-C base pairs display a transient absorption band characteristic of the short-lived G+• cation radical. The mini-hairpins with 1-3 A-T base pairs do not display the transient absorption band characteristic of the (An+•) polaron. This implies that an A-tract with three base pairs is too short to support polaron formation.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 7042-7047 |
| Number of pages | 6 |
| Journal | Journal of Physical Chemistry B |
| Volume | 121 |
| Issue number | 29 |
| DOIs | |
| State | Published - Jul 27 2017 |
Funding
This research was funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division under Awards DE-FG02-96ER14604 (F.D.L.) and DE-FG02-99ER14999 (M.R.W).
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry