Low energy (0-12 eV) electron interaction with gas phase building blocks of DNA/RNA

We review recent results on dissociative electron attachment (DEA) to gas phase D-ribose, tetraacetyl-D-ribose (TAR) and dibutylphosphate (DBP), which serve as model compounds for the DNA or RNA backbone. New results are presented on negative ion formation in D-ribose probed by matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry. The two methods reveal that the transient D-ribose anion R^-# decomposes in the same way like the deprotonated D-ribose molecule [R-H]^-, i.e. by abstraction of different numbers of water and formaldehyde units. In DEA the TNI R^-# is generated at very low energies close to 0 eV most likely through a vibrational feshbach resonance. The fragmentation pattern and the characteristic resonances of D-ribose are preserved in TAR, where a furanose is bound to four acetyl groups. The presence of an acetyl group leads additionally to fragmentation through a shape resonance. Shape resonances were also observed in DBP, followed by C-O and P-O bond breaking.