Publication – Wachtveitl

The three possible 2-(pyrenylethynyl) adenosines: rotameric energy barriers govern the photodynamics of these structural isomers.

Reuss AJ, Grünewald C, Braun M, Engels JW, Wachtveitl J. Chemphyschem. 2015 Dec 4. Abstract or full publication here.

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 along with time-resolved fluorescence emission experiments in different solvents, in order 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 multiexponential. These features in the ultrafast dynamics are indicative of the rotational energy barriers in the first excited state.