The degree of electronic coupling between DNA bases is a topic being up for much debate. Here we report on the intrinsic electronic properties of isolated DNA strands in vacuo free of solvent, which is a good starting point for high-level excited states calculations. Action spectra of DNA single strands of adenine reveal sign of exciton coupling between stacked bases from blueshifted absorption bands (∼3 nm) relative to that of the dAMP mononucleotide (one adenine base). The bands are blueshifted by about 10 nm compared to those of solvated strands, which is a shift similar to that for the adenine molecule and the dAMP mononucleotide. Desolvation has little effect on the bandwidth, which implies that inhomogenous broadening of the absorption bands in aqueous solution is of minor importance compared to, e.g., conformational disorder. Finally, at high photon energies, internal conversion competes with electron detachment since dissociation of the bare photoexcited ions on the microsecond time scale is measured.

1.
C. E.
Crespo-Hernández
,
B.
Cohen
,
P. M.
Hare
, and
B.
Kohler
,
Chem. Rev.
104
,
1977
(
2004
).
2.
C. T.
Middleton
,
K.
de La Harpe
,
C.
Su
,
Y. K.
Law
,
C. E.
Crespo-Hernández
, and
B.
Kohler
,
Annu. Rev. Phys. Chem.
60
,
217
(
2009
).
3.
S. Brøndsted
Nielsen
,
J. U.
Andersen
,
J. S.
Forster
,
P.
Hvelplund
,
B.
Liu
,
U. V.
Pedersen
, and
S.
Tomita
,
Phys. Rev. Lett.
91
,
048302
(
2003
).
4.
C. E.
Crespo-Hernández
,
B.
Cohen
, and
B.
Kohler
,
Nature (London)
436
,
1141
(
2005
).
5.
D.
Markovitsi
,
F.
Talbot
,
T.
Gustavsson
,
D.
Onidas
,
E.
Lazzarotto
, and
S.
Marguet
,
Nature (London)
441
,
E7
(
2006
).
6.
I.
Buchvarov
,
Q.
Wang
,
M.
Raytchev
,
A.
Trifonov
, and
T.
Fiebig
,
Proc. Natl. Acad. Sci. U.S.A.
104
,
4794
(
2007
).
7.
D.
Markovitsi
,
T.
Gustavsson
, and
A.
Banyasz
,
Mutat. Res. Rev.
704
,
21
(
2010
).
8.
A. I. S.
Holm
,
L. M.
Nielsen
,
S. V.
Hoffmann
, and
S. Brøndsted
Nielsen
,
Phys. Chem. Chem. Phys.
12
,
9581
(
2010
).
9.
U.
Kadhane
,
A. I. S.
Holm
,
S. V.
Hoffmann
, and
S. Brøndsted
Nielsen
,
Phys. Rev. E
77
,
021901
(
2008
).
10.
I.
Vayá
,
T.
Gustavsson
,
F.-A.
Miannay
,
T.
Douki
, and
D.
Markovitsi
,
J. Am. Chem. Soc.
132
,
11834
(
2010
).
11.
D.
Markovitsi
,
T.
Gustavsson
, and
I.
Vayá
,
J. Phys. Chem. Lett.
1
,
3271
(
2010
).
12.
B.
Kohler
,
J. Phys. Chem. Lett.
1
,
2047
(
2010
).
13.
F.
Santoro
,
V.
Barone
, and
R.
Improta
,
J. Am. Chem. Soc.
131
,
15232
(
2009
).
14.
A. W.
Lange
and
J. M.
Herbert
,
J. Am. Chem. Soc.
131
,
3913
(
2009
).
15.
J. C.
Genereux
and
J. K.
Barton
,
Chem. Rev.
110
,
1642
(
2010
).
16.
B.
Bouvier
,
J.-P.
Dognon
,
R.
Lavery
,
D.
Markovitsi
,
P.
Millié
,
D.
Onidas
, and
K.
Zakrzewska
,
J. Phys. Chem. B
107
,
13512
(
2003
).
17.
S. P.
Møller
,
Nucl. Instrum. Methods Phys. Res. A
394
,
281
(
1997
).
18.
J. U.
Andersen
,
P.
Hvelplund
,
S. Brøndsted
Nielsen
,
S.
Tomita
,
H.
Wahlgreen
,
S. P.
Møller
,
U. V.
Pedersen
,
J. S.
Forster
, and
T. J. D.
Jørgensen
,
Rev. Sci. Instrum.
73
,
1284
(
2002
).
19.
K.
Støchkel
,
U.
Kadhane
,
J. U.
Andersen
,
A. I. S.
Holm
,
P.
Hvelplund
,
M.-B. S.
Kirketerp
,
M. K.
Larsen
,
M. K.
Lykkegaard
,
S. Brøndsted
Nielsen
,
S.
Panja
, and
H.
Zettergren
,
Rev. Sci. Instrum.
79
,
023107
(
2008
).
20.
J.
Gidden
and
M. T.
Bowers
,
Eur. Phys. J. D
20
,
409
(
2002
).
21.
B.
Liu
,
P.
Hvelplund
,
S. Brøndsted
Nielsen
, and
S.
Tomita
,
Phys. Rev. A
74
,
052704
(
2006
).
22.
J. C.
Marcum
,
A.
Halevi
, and
J. M.
Weber
,
Phys. Chem. Chem. Phys.
11
,
1740
(
2009
).
23.
J. A.
Wyer
and
S. Brøndsted
Nielsen
,
J. Chem. Phys.
133
,
084306
(
2010
).
24.
See supplementary material at http://dx.doi.org/10.1063/1.3679444 for action spectra of dA3 and dA4 based on a one-photon analysis.
25.
L.
Li
and
D. M.
Lubman
,
Anal. Chem.
59
,
2538
(
1987
).
26.
X.
Yang
,
X.-B.
Wang
,
E. R.
Vorpagel
, and
L.-S.
Wang
,
Proc. Natl. Acad. Sci U.S.A.
101
,
17588
(
2004
).
27.
Z. Q.
Guan
,
N. L.
Kelleher
,
P. B.
O’Connor
,
D. J.
Aaserud
,
D. P.
Little
, and
F. W.
McLafferty
,
Int. J. Mass Spectrom. Ion Process.
158
,
357
(
1996
).
28.
V.
Gabelica
,
F.
Rosu
,
T.
Tabarin
,
C.
Kinet
,
R.
Antoine
,
M.
Broyer
,
E.
De Pauw
, and
P.
Dugourd
,
J. Am. Chem. Soc.
129
,
4706
(
2007
).
29.
V.
Gabelica
,
T.
Tabarin
,
R.
Antoine
,
F.
Rosu
,
I.
Compagnon
,
M.
Broyer
,
E.
De Pauw
, and
P.
Dugourd
,
Anal. Chem.
78
,
6564
(
2006
).

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