Effects of dehydrocarbon atom separation on the reactivity of aromatic σ,σ-biradicals toward dinucleoside phosphates

ANYL 126

Nishi S Rochelle, nrochell@purdue.edu, Linan Yang, and Hilkka I. Kenttämaa, hilkka@purdue.edu. Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47906
Aromatic σ,σ-biradical intermediates are potent DNA cleavers but their high cytotoxicity has limited their medical use. To overcome this challenge, it is essential to better understand their interactions with DNA. The short lifetime of radicals hinders their examination in solution. Therefore, gas-phase studies were carried out in a high vacuum FT-ICR mass spectrometer. A charged group was added to the biradicals to allow their manipulation in the mass spectrometer. Laser-induced acoustic desorption was used to evaporate thermally labile biomolecules intact into the mass spectrometer. The results demonstrate that in addition to the magnitude of the singlet-triplet gap and electron affinity, the dehydrocarbon atom separation can also influence the reactions of biradicals with dinucleoside phosphates. A larger dehydrocarbon atom separation lowers the transition state energy by lowering the energetic cost to uncouple the biradical electrons in the transition state.
 

General Posters
7:00 PM-9:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Analytical Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007