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The Three Possible 2‐(Pyrenylethynyl) Adenosines: Rotameric Energy Barriers Govern the Photodynamics of These Structural Isomers
Author(s) -
Reuss Andreas J.,
Grünewald Christian,
Braun Markus,
Engels Joachim W.,
Wachtveitl Josef
Publication year - 2016
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201500958
Subject(s) - ultrafast laser spectroscopy , excited state , nanosecond , fluorescence , chemistry , chemical physics , spectroscopy , photochemistry , ultrashort pulse , time resolved spectroscopy , fluorescence spectroscopy , adenosine , atomic physics , physics , quantum mechanics , laser , biochemistry
This article presents a comprehensive study of the photophysics of 2‐(2‐pyrenylethynyl) adenosine and 2‐(4‐pyrenylethynyl) adenosine, which are structural isomers of the well‐established fluorescent RNA label 2‐(1‐pyrenylethynyl) adenosine. We performed steady‐state and ultrafast transient absorption spectroscopy studies along with time‐resolved fluorescence emission experiments in different solvents to work out the interplay of locally excited and charge‐transfer states. We found the ultrafast photodynamics to be crucial for the fluorescence decay behavior, which extends up to tens of nanoseconds and is partially multi‐exponential. These features in the ultrafast dynamics are indicative of the rotational energy barriers in the first excited state.