EMSL: Maciej S Gutowski's Publications

Eustis S, D Radisic, KH Bowen, RA Bachorz, M Haranczyk, GK Schenter, and MS Gutowski. 2008. "Electron-Driven Acid-Base Chemistry: Proton Transfer from Hydrogen Chloride to Ammonia." Science 319(5865):936-939. doi:10.1126/science.1151614 Abstract It is well established that NH3 and HCl form in isolation a hydrogen bonded complex NH3…HCl rather than an ionic salt, NH4+Cl-. This experimental and theoretical study utilized anion photoelectron spectroscopy and ab initio theory to investigate the effect of an excess electron on the hydrogen bonded complex NH3 …HCl. Our results indicate that one electron is sufficient to drive the hydrogen bonded complex to form the ionic salt. We propose a stepwise mechanism for this process involving an initial dipole-bound state, followed by the formation of a distorted Rydberg species, NH40.

Haranczyk M, MS Gutowski, X Li, and KH Bowen. 2007. "Bound Anionic States of Aadenine." Proceedings of the National Academy of Sciences of the United States of America 104(12):4804-4807. doi:10.1073/pnas.0609982104 Abstract The research described in this product was performed in part in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. Anionic states of nucleic acid bases are involved in DNA damage by low-energy electrons and in charge transfer through DNA. Previous gas phase studies of free, unsolvated nucleic acid base parent anions probed only dipole-bound states, which are not present in condensed phase environments, but did not observe valence anionic states, which for purine bases are thought to be adiabatically unbound. Contrary to this expectation,wehave demonstrated that some thus far ignored tautomers of adenine, which result from enamine-imine transformations, support valence anionic states with electron vertical detachment energies as large as 2.2 eV, and at least one of these anionic tautomers is adiabatically bound. Moreover, we predict that the new anionic tautomers should also dominate in solutions and should be characterized by larger values of electron vertical detachment energy than the canonical valence anion. All of the newfound anionic tautomers might be formed in the course of dissociative electron attachment followed by a hydrogen atom attachment to a carbon atom, and they might affect the structure and properties of DNA and RNA exposed to low-energy electrons. The new valence states observed here, unlike the dipole-bound state, could exist in condensed phases and might be relevant to radiobiological damage. The discovery of these valence anionic states of adenine was facilitated by the development of (i) an experimental method for preparing parent anions of nucleic acid bases for photoelectron experiments, and (ii) a combinatorial/quantum chemical approach for identification of the most stable tautomers of organic molecules.

Haranczyk M, MS Gutowski, X Li, and KH Bowen. 2007. "Bound anionic states of adenine." Proceedings of the National Academy of Sciences of the United States of America 104(12):4804-4807. doi:10.1073/pnas.0609982104 Abstract Anionic states of nucleic acid bases are involved in DNA damage by low-energy electrons and in charge transfer through DNA. Previous gas phase studies of free, unsolvated nucleic acid base parent anions probed only dipole-bound states, which are not present in condensed phase environments, but did not observe valence anionic states, which for purine bases, are thought to be adiabatically unbound. Contrary to this expectation, we have demonstrated that some thus far ignored tautomers of adenine, which result from enamine-imine transformations, support valence anionic states with electron vertical detachment energies as large as 2.2 eV, and at least one of these anionic tautomers is adiabatically bound. Moreover, we predict that the new anionic tautomers should also dominate in solutions and should be characterized by larger values of electron vertical detachment energy than the canonical valence anion. All of the new-found anionic tautomers might be formed in the course of dissociative electron attachment followed by a hydrogen atom attachment to a carbon atom, and they might affect the structure and properties of DNA and RNA exposed to low-energy electrons. The discovery of these valence anionic states of adenine was facilitated by the development of: (i) a new experimental method for preparing parent anions of nucleic acid bases for photoelectron experiments, and (ii) a new combinatorial/ quantum chemical approach for identification of the most stable tautomers of organic molecules. The computational portion of this work was supported by the: (i) Polish State Committee for Scientific Research (KBN) Grants: DS/8000-4-0140-7 (M.G.) and N204 127 31/2963 (M.H.), (ii) European Social Funds (EFS) ZPORR/2.22/II/2.6/ARP/U/2/05 (M.H.), and (iii) US DOE Office of Biological and Environmental Research, Low Dose Radiation Research Program (M.G.). M.H. holds the Foundation for Polish Science (FNP) award for young scientists. The calculations were performed at the Academic Computer Center in Gdańsk (TASK) and at the Molecular Science Computing Facility (MSCF) in the William R. Wiley Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the U.S. DOE OBER and located at PNNL, which is operated by Battelle for the US DOE. The MSCF resources were available through a Computational Grand Challenge Application grant. The experimental material in this paper (K.H.B.) is based upon work supported by the National Science Foundation under Grant No. CHE-0517337.

Haranczyk M, MS Gutowski, X Li, and KH Bowen. 2007. "Bound Anionic States of Adenine ." Proceedings of the National Academy of Sciences of the United States of America 104(12):4804-4807. doi:10.1073/pnas.0609982104 Abstract The research described in this product was performed in part in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. Anionic states of nucleic acid bases are involved in DNA damage by low-energy electrons and in charge transfer through DNA. Previous gas phase studies of free, unsolvated nucleic acid base parent anions probed only dipole-bound states, which are not present in condensed phase environments, but did not observe valence anionic states, which for purine bases are thought to be adiabatically unbound. Contrary to this expectation, we have demonstrated that some thus far ignored tautomers of adenine, which result from enamine-imine transformations, support valence anionic states with electron vertical detachment energies as large as 2.2 eV, and at least one of these anionic tautomers is adiabatically bound. Moreover, we predict that the new anionic tautomers should also dominate in solutions and should be characterized by larger values of electron vertical detachment energy than the canonical valence anion. All of the newfound anionic tautomers might be formed in the course of dissociative electron attachment followed by a hydrogen atom attachment to a carbon atom, and they might affect the structure and properties of DNA and RNA exposed to low-energy electrons. The new valence states observed here, unlike the dipole-bound state, could exist in condensed phases and might be relevant to radiobiological damage. The discovery of these valence anionic states of adenine was facilitated by the development of (i) an experimental method for preparing parent anions of nucleic acid bases for photoelectron experiments, and (it) a combinatorial/quantum chemical approach for identification of the most stable tautomers of organic molecules.

Haranczyk M, JH Miller, and MS Gutowski. 2007. "Differences in Electrostatic Potential Around DNA Fragments Containing Adenine and 8-oxo-Adenine. An Analysis Based on Regular Cylindrical Projection ." Journal of Molecular Graphics and Modelling 26(1):282-289. Abstract Changes of electrostatic potential (EP) around the DNA molecule resulting from chemical modifications of nucleotides may play a role in enzymatic recognition of damaged sites. Effects of chemical modifications of nucleotides on the structure of DNA have been characterized through large scale density functional theory computations. Quantum mechanical structural optimizations of DNA fragments with three pairs of nucleotides and accompanying counteractions were performed with a B3LYP exchange-correlation functional and 6-31G** basis sets. The “intact” DNA fragment contained adenine in the middle layer, while the “damaged” fragment had the adenine replaced with 8-oxo-adenine. The electrostatic potential around these DNA fragments was projected on a cylindrical surface around the double helix. The two-dimensional maps of EP of the intact and damaged DNA fragments were analyzed to identify these modifications of EP that result from the occurrence of 8-oxo-adenine (8oA). It was found that distortions of a phosphate group neighboring 8oA and displacements of the accompanying countercation are clearly reflected in the EP maps. Helpful discussions Michel Dupuis are gratefully acknowledged. Authors wish to thank Marcel Swart for directing us to a compilation of van der Waals radii. This work was supported by the: (i) US DOE Office of Biological and Environmental Research, Low Dose Radiation Research Program (M.G. and M.H.), (ii) the Office of Science (BER), U. S. Department of Energy, Grant No. DE-FG03-02ER63470 (JHM), (iii) Polish State Committee for Scientific Research (KBN) Grant DS/8221-4-0140-6 (MG), (iv) European Social Funds (EFS) ZPORR/2.22/II/2.6/ARP/U/2/05 (M.H.). M.H. holds the Foundation for Polish Science (FNP) award for young scientists. The calculations were performed at the Academic Computer Center in Gdańsk (TASK) and at the Molecular Science Computing Facility (MSCF) in the William R. Wiley Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the U.S. Department of Energy's Office of Biological and Environmental Research and located at the Pacific Northwest National Laboratory, which is operated by Battelle for the US Department of Energy. The MSCF resources were available through a pilot project.

Haranczyk M, and MS Gutowski. 2007. "Differences in Electrostatic Potential Around DNA Fragments Containing Guanine and 8-oxo-Guanine." Theoretical Chemistry Accounts 117(2):291-296. doi:10.1007/s00214-006-0133-1 Abstract hanges of electrostatic potential (EP) around the DNA molecule resulting from chemical modifications of nucleotides may play a role in enzymatic recognition of damaged sites. Effects of chemical modifications of nucleotides on the structure of DNA have been characterized through large scale density functional theory computations. Quantum mechanical structural optimizations of DNA fragments with three pairs of nucleotoides and accompanying counteractions were performed with a B3LYP exchange-correlation functional and 6-31G** basis sets. The “intact” DNA fragment contained guanine in the middle layer, while the “damaged” fragment had the guanine replaced with 8-oxo-guanine. The electrostatic potential around these DNA fragments was projected on a surface around the double helix. The 2D maps of EP of intact and damaged DNA fragments were analyzed to identify these modifications of EP that result from the occurrence of 8-oxo-guanine. It was found that distortions of the phosphate groups and displacements of the accompanying countercations are clearly reflected in the EP maps.

Li X, KH Bowen, M Haranczyk, RA Bachorz, K Mazurkiewicz, J Rak, and MS Gutowski. 2007. "Photoelectron Spectroscopy of Adiabatically Bound Valence Anions of Rare Tautomers of the Nucleic Acid Bases." Journal of Chemical Physics 127(17):Art. 174309. doi:10.1063/1.2795719 Abstract The research described in this product was performed in part in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. Anionic states of nucleic acid bases (NABs) are involved in DNA damage by low-energy electrons and in charge transfer through DNA. Previous gas phase studies of free, unsolvated NAB parent anions probed mostly dipole-bound states, which are not present in condensed phase environments. Recently, we demonstrated that very rare tautomers of uracil (U), cytosine (C), adenine (A), and guanine (G), which are obtained from canonical tautomers through N-to-C proton transfers, support valence anionic states. Here we report the photoelectron spectrum of the final member of the NABs series: the valence state of the thymine (T) anion. Additionally, we summarized the work of all five NABs. All of the newfound anionic tautomers of the NABs may be formed via dissociative electron attachment followed by hydrogen atom reattachment to a carbon atom. Furthermore, these unusual tautomers may affect the structure and properties of DNA and RNA exposed to low-energy electrons. The new valence states observed here, unlike dipole bound states, could exist in condensed phases and may be relevant to radiobiological damage.

Mazurkiewicz K, M Haranczyk, MS Gutowski, and J Rak. 2007. "Can an Excess Electron Localise on a Purine Moiety in the Adenine-thymine Watson-Crick Base Pair? A Computational Study." International Journal of Quantum Chemistry 107(12):2224-2232. doi:10.1002/qua.21359 Abstract The electron affinity and the propensity to electron-induced proton transfer (PT) of hydrogen-bonded complexes between the Watson–Crick adenine–thymine pair (AT) and simple organic acid (HX), attached to adenine in the Hoogsteen-type configuration, were studied at the B3LYP/6-31+G** level. Although the carboxyl group is deprotonated at physiological pH, its neutral form, COOH, resembles the peptide bond or the amide fragment in the side chain of asparagine (Asn) or glutamine (Gln). Thus, these complexes mimic the interaction between the DNA environment (e.g., proteins) and nucleobase pairs incorporated in the biopolymer. Electron attachment is thermodynamically feasible and adiabatic electron affinities range from 0.41 to 1.28 eV, while the vertical detachment energies of the resulting anions span the range of 0.39 –2.88 eV. Low-energy activation barriers separate the anionic minima: aHX(AT) from the more stable single-PT anionic geometry, aHX(AT)-SPT, and aHX(AT)-SPT from the double-PT anionic geometry, aHX(AT)-DPT. Interaction between the adenine of the Watson–Crick AT base pair with an acidic proton donor probably counterbalances the larger EA of isolated thymine, as SOMO is almost evenly delocalized over both types of nucleic bases in the aHX(AT) anions. Moreover, as a result of PT the excess electron localizes entirely on adenine. Thus, in DNA interacting with its physiological environment, damage induced by low-energy electrons could begin, contrary to the current view, with the formation of purine anions, which are not formed in isolated DNA because of the greater stability of anionic pyrimidines.

Mazurkiewicz K, M Haranczyk, MS Gutowski, J Rak, D Radisic, S Eustis, D Wang, and KH Bowen. 2007. "Valence anions in complexes of adenine and 9-methyladenine with formic acid - stabilization by intermolecular proton transfer." Journal of the American Chemical Society 129(5):1216-1224. doi:10.1021/ja066229h Abstract The photoelectron spectra of the adenine-formic acid (AFA)- and 9-methyladenine-formic acid (MAFA)- anionic complexes have been recorded with 2.540 eV photons. These spectra reveal broad features with maxima at 1.5-1.4 eV that indicate formation of stable valence anions in the gas phase. The neutral and anionic complexes of adenine/9- methyladenine and formic acid were also studied computationally at the B3LYP, second order Møller-Plesset and coupled clusters levels of theory, with the 6-31++G** and aug-cc-pVDZ basis sets. The neutral complexes form cyclic hydrogen bonds and the most stable dimers are bound by 17.7 and 16.0 kcal/mol for AFA and MAFA, respectively. The theoretical results indicate that the excess electron in both (AFA)- and (MAFA)- occupies a p* orbital localized on adenine/9-methyladenine and the adiabatic stability of the most stable anions amounts to 0.67 and 0.54 eV for AFA- and MAFA-, respectively. The excess electron attachment to the complexes induces a barrierfree proton transfer (BFPT) from the carboxylic group of formic acid to a N atom of adenine or 9-mathyladenine. As a result, the most stable structures of the anionic complexes can be characterized as neutral radicals of hydrogenated adenine(9-methyladenine) solvated by a deprotonated formic acid. The BFPT to the N atoms of adenine may be biologically relevant because some of these sites are not involved in the Watson-Crick pairing scheme and are easily accessible in the cellular environment. We suggest that valence anions of purines might be as important as those of pyrimidines in the process of DNA damage by low energy electrons. The calculations were performed at the Academic Computer Center in Gdańsk (TASK) and at the Molecular Science Computing Facility (MSCF) in the William R. Wiley Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the U.S. Department of Energy's Office of Biological and Environmental Research and located at the Pacific Northwest National Laboratory, which is operated by Battelle for the US Department of Energy. The MSCF resources were available through a Computational Grand Challenge Application grant.

Gutowski MS, and T Autrey. 2006. "Hydrogen Gets Onboard." Chemistry World (March 2006):, doi:www.rsc.org/chemistryworld/Issues/2006/March Abstract In this brief review we update progress in research efforts for on-board hydrogen storage for fuel cell powered vehicles. In addition to economic targets, the technological challenges are bounded by volumetric and gravimetric constraints. Specifically, an amoiunt of 4 kg of H2, required to propel a highly fuel efficient automobile for 500 kilometers, must fit into the space of a conventional gasoline tank. The volumetric constraints rule out compressed and liquefied H2 and teach us that hydrogen must be stored as a solid material, either by physi-sorption to high surface area materials or chemically bond (covalent or ionic) to light weight elements. Hydrogen stored on high surface area materials is weakly bound and general requires low temperatures to stabilize the hydrogen. On the other end, hydrogen covalently bound to light metals requires high temperatures to release the hydrogen. One interesting alterative is chemical hydrogen storage (CHS). CHS covers a broad range of materials but is defined as a process whereby the hydrogen is released by a chemical reaction. The reaction could be induced by hydrolysis, a reaction with water, or by thermolysis, heating to moderate temperatures to release hydrogen. The spent material can then be reprocessed or regenerated off-board. Battelle operates the Pacific Northwest National Laboratory for the US Department of Energy.