TY - JOUR
T1 - Dynamics of Charge Injection and Charge Recombination in DNA Mini-Hairpins
AU - Mishra, Ashutosh Kumar
AU - Harris, Michelle A.
AU - Young, Ryan M.
AU - Wasielewski, Michael R.
AU - Lewis, Frederick D.
N1 - Funding Information:
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).
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/7/27
Y1 - 2017/7/27
N2 - 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.
AB - 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.
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U2 - 10.1021/acs.jpcb.7b03084
DO - 10.1021/acs.jpcb.7b03084
M3 - Article
C2 - 28628320
AN - SCOPUS:85026543446
VL - 121
SP - 7042
EP - 7047
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
SN - 1520-6106
IS - 29
ER -