Formation and decay of localized contact radical ion pairs in DNA hairpins

Frederick D. Lewis, Xiaoyang Liu, Scott E. Miller, Ryan T. Hayes, Michael R Wasielewski

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

The dynamics of charge separation and charge recombination in synthetic DNA hairpins possessing diphenylacetylene-4,4′-dicarboxamide linkers have been investigated by means of femtosecond time-resolved transient absorption spectroscopy. The lowest excited singlet state of the linker is capable of oxidizing nearest neighbor adenine as well as guanine. A large wavelength shift in the transient absorption spectrum accompanies the conversion of the singlet linker to its anion radical, facilitating the investigation of electron-transfer dynamics. The rate constants for charge separation are dependent upon the oxidation potentials of the neighboring nucleobase donors but not upon the identity of nonnearest neighbors. Thus, the charge separation processes yield a contact radical ion pair in which the positive charge is localized on the neighboring nucleobase. Rate constants for charge recombination are dependent upon the identity of the first and second nearest-neighbor nucleobases but not more remote bases. This dependence is attributed to stabilization of the contact radical ion pair by interaction with its nearest neighbor. The absence of charge migration to form a base-pair separated radical ion pair is a consequence of Coulombic attraction in the contact radical ion pair and the low effective dielectric constant (ε <7) experienced by the contact radical ion pair. Photoinduced charge injection to form a base-pair separated radical ion pair is necessary in order to observe charge migration.

Original languageEnglish
Pages (from-to)14020-14026
Number of pages7
JournalJournal of the American Chemical Society
Volume124
Issue number47
DOIs
Publication statusPublished - Nov 27 2002

Fingerprint

DNA
Ions
Base Pairing
Genetic Recombination
Rate constants
Charge injection
Guanine
Adenine
Absorption spectroscopy
Excited states
Anions
Absorption spectra
Spectrum Analysis
Permittivity
Negative ions
Stabilization
Electrons
Wavelength
Oxidation
Injections

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Formation and decay of localized contact radical ion pairs in DNA hairpins. / Lewis, Frederick D.; Liu, Xiaoyang; Miller, Scott E.; Hayes, Ryan T.; Wasielewski, Michael R.

In: Journal of the American Chemical Society, Vol. 124, No. 47, 27.11.2002, p. 14020-14026.

Research output: Contribution to journalArticle

Lewis, Frederick D. ; Liu, Xiaoyang ; Miller, Scott E. ; Hayes, Ryan T. ; Wasielewski, Michael R. / Formation and decay of localized contact radical ion pairs in DNA hairpins. In: Journal of the American Chemical Society. 2002 ; Vol. 124, No. 47. pp. 14020-14026.
@article{8d1ea3e2d65e42a2baf8a40fb8a72020,
title = "Formation and decay of localized contact radical ion pairs in DNA hairpins",
abstract = "The dynamics of charge separation and charge recombination in synthetic DNA hairpins possessing diphenylacetylene-4,4′-dicarboxamide linkers have been investigated by means of femtosecond time-resolved transient absorption spectroscopy. The lowest excited singlet state of the linker is capable of oxidizing nearest neighbor adenine as well as guanine. A large wavelength shift in the transient absorption spectrum accompanies the conversion of the singlet linker to its anion radical, facilitating the investigation of electron-transfer dynamics. The rate constants for charge separation are dependent upon the oxidation potentials of the neighboring nucleobase donors but not upon the identity of nonnearest neighbors. Thus, the charge separation processes yield a contact radical ion pair in which the positive charge is localized on the neighboring nucleobase. Rate constants for charge recombination are dependent upon the identity of the first and second nearest-neighbor nucleobases but not more remote bases. This dependence is attributed to stabilization of the contact radical ion pair by interaction with its nearest neighbor. The absence of charge migration to form a base-pair separated radical ion pair is a consequence of Coulombic attraction in the contact radical ion pair and the low effective dielectric constant (ε <7) experienced by the contact radical ion pair. Photoinduced charge injection to form a base-pair separated radical ion pair is necessary in order to observe charge migration.",
author = "Lewis, {Frederick D.} and Xiaoyang Liu and Miller, {Scott E.} and Hayes, {Ryan T.} and Wasielewski, {Michael R}",
year = "2002",
month = "11",
day = "27",
doi = "10.1021/ja027108u",
language = "English",
volume = "124",
pages = "14020--14026",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "47",

}

TY - JOUR

T1 - Formation and decay of localized contact radical ion pairs in DNA hairpins

AU - Lewis, Frederick D.

AU - Liu, Xiaoyang

AU - Miller, Scott E.

AU - Hayes, Ryan T.

AU - Wasielewski, Michael R

PY - 2002/11/27

Y1 - 2002/11/27

N2 - The dynamics of charge separation and charge recombination in synthetic DNA hairpins possessing diphenylacetylene-4,4′-dicarboxamide linkers have been investigated by means of femtosecond time-resolved transient absorption spectroscopy. The lowest excited singlet state of the linker is capable of oxidizing nearest neighbor adenine as well as guanine. A large wavelength shift in the transient absorption spectrum accompanies the conversion of the singlet linker to its anion radical, facilitating the investigation of electron-transfer dynamics. The rate constants for charge separation are dependent upon the oxidation potentials of the neighboring nucleobase donors but not upon the identity of nonnearest neighbors. Thus, the charge separation processes yield a contact radical ion pair in which the positive charge is localized on the neighboring nucleobase. Rate constants for charge recombination are dependent upon the identity of the first and second nearest-neighbor nucleobases but not more remote bases. This dependence is attributed to stabilization of the contact radical ion pair by interaction with its nearest neighbor. The absence of charge migration to form a base-pair separated radical ion pair is a consequence of Coulombic attraction in the contact radical ion pair and the low effective dielectric constant (ε <7) experienced by the contact radical ion pair. Photoinduced charge injection to form a base-pair separated radical ion pair is necessary in order to observe charge migration.

AB - The dynamics of charge separation and charge recombination in synthetic DNA hairpins possessing diphenylacetylene-4,4′-dicarboxamide linkers have been investigated by means of femtosecond time-resolved transient absorption spectroscopy. The lowest excited singlet state of the linker is capable of oxidizing nearest neighbor adenine as well as guanine. A large wavelength shift in the transient absorption spectrum accompanies the conversion of the singlet linker to its anion radical, facilitating the investigation of electron-transfer dynamics. The rate constants for charge separation are dependent upon the oxidation potentials of the neighboring nucleobase donors but not upon the identity of nonnearest neighbors. Thus, the charge separation processes yield a contact radical ion pair in which the positive charge is localized on the neighboring nucleobase. Rate constants for charge recombination are dependent upon the identity of the first and second nearest-neighbor nucleobases but not more remote bases. This dependence is attributed to stabilization of the contact radical ion pair by interaction with its nearest neighbor. The absence of charge migration to form a base-pair separated radical ion pair is a consequence of Coulombic attraction in the contact radical ion pair and the low effective dielectric constant (ε <7) experienced by the contact radical ion pair. Photoinduced charge injection to form a base-pair separated radical ion pair is necessary in order to observe charge migration.

UR - http://www.scopus.com/inward/record.url?scp=0037184480&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037184480&partnerID=8YFLogxK

U2 - 10.1021/ja027108u

DO - 10.1021/ja027108u

M3 - Article

C2 - 12440900

AN - SCOPUS:0037184480

VL - 124

SP - 14020

EP - 14026

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 47

ER -