title: Automated quantum chemistry based molecular dynamics simulations of electron ionization induced fragmentations of the nucleobases Uracil, Thymine, Cytosine, and Guanine.
abstract: The gas-phase decomposition pathways of electron ionization (EI)-induced radical cations of the nucleobases uracil, thymine, cytosine, and guanine are investigated by means of mixed quantum-classical molecular dynamics. No preconceived fragmentation channels are used in the calculations. The results compare well to a plethora of experimental and theoretical data for these important biomolecules. With our combined stochastic and dynamic approach, one can access in an unbiased way the energetically available decomposition mechanisms. Additionally, we are able to separate the EI mass spectra of different tautomers of cytosine and guanine. Our method (previously termed quantum chemistry electron ionization mass spectra) reproduces free nucleobase experimental mass spectra well and provides detailed mechanistic in-sight into high-energy unimolecular decomposition processes.
authors: Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie der Rheinischen Friedrich- Wilhelms-Universität Bonn, Beringstr. 4, D-53115, Bonn, Germany. grimme@thch.uni- bonn.de.
authors: Stefan
authors: S
authors: Grimme
authors: Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie der Rheinischen Friedrich-Wilhelms-Universität Bonn, Beringstr. 4, D-53115, Bonn, Germany. christoph.bauer@thch.uni-bonn.de.
authors: Christopher Alexander
authors: CA
authors: Bauer
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D003596:Cytosine / Q000032:analysis / Q000737:chemistry; D053938:DNA Fragmentation; D006147:Guanine / Q000032:analysis / Q000737:chemistry; D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D009711:Nucleotides / Q000032:analysis* / Q000737:chemistry*; D011789:Quantum Theory; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013941:Thymine / Q000032:analysis / Q000737:chemistry; D014498:Uracil / Q000032:analysis / Q000737:chemistry
chemical_list: D009711:Nucleotides; D014498:Uracil; D006147:Guanine; D003596:Cytosine; D013941:Thymine