ALBERT

Description: All previous experimental and theoretical studies of molecular interactions at metal surfaces show that electronically nonadiabatic influences increase with molecular velocity. We report the observation of a nonadiabatic electronic effect that follows the opposite trend: The probability of electron emission from a low-work function surface--Au(111) capped by half a monolayer of Cs--increases as the velocity of the incident NO molecule decreases during collisions with highly vibrationally excited NO(X(2)pi((1/2)), V = 18; V is the vibrational quantum number of NO), reaching 0.1 at the lowest velocity studied. We show that these results are consistent with a vibrational autodetachment mechanism, whereby electron emission is possible only beyond a certain critical distance from the surface. This outcome implies that important energy-dissipation pathways involving nonadiabatic electronic excitations and, furthermore, not captured by present theoretical methods may influence reaction rates at surfaces.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nahler, N H -- White, J D -- Larue, J -- Auerbach, D J -- Wodtke, A M -- New York, N.Y. -- Science. 2008 Aug 29;321(5893):1191-4. doi: 10.1126/science.1160040.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA 93106-9510, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18755972" target="_blank"〉PubMed〈/a〉

Description: We used the Linac Coherent Light Source free-electron x-ray laser to probe the electronic structure of CO molecules as their chemisorption state on Ru(0001) changes upon exciting the substrate by using a femtosecond optical laser pulse. We observed electronic structure changes that are consistent with a weakening of the CO interaction with the substrate but without notable desorption. A large fraction of the molecules (30%) was trapped in a transient precursor state that would precede desorption. We calculated the free energy of the molecule as a function of the desorption reaction coordinate using density functional theory, including van der Waals interactions. Two distinct adsorption wells-chemisorbed and precursor state separated by an entropy barrier-explain the anomalously high prefactors often observed in desorption of molecules from metals.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dell'Angela, M -- Anniyev, T -- Beye, M -- Coffee, R -- Fohlisch, A -- Gladh, J -- Katayama, T -- Kaya, S -- Krupin, O -- LaRue, J -- Mogelhoj, A -- Nordlund, D -- Norskov, J K -- Oberg, H -- Ogasawara, H -- Ostrom, H -- Pettersson, L G M -- Schlotter, W F -- Sellberg, J A -- Sorgenfrei, F -- Turner, J J -- Wolf, M -- Wurth, W -- Nilsson, A -- New York, N.Y. -- Science. 2013 Mar 15;339(6125):1302-5. doi: 10.1126/science.1231711.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉University of Hamburg and Center for Free Electron Laser Science, Hamburg, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23493709" target="_blank"〉PubMed〈/a〉

Description: Femtosecond x-ray laser pulses are used to probe the carbon monoxide (CO) oxidation reaction on ruthenium (Ru) initiated by an optical laser pulse. On a time scale of a few hundred femtoseconds, the optical laser pulse excites motions of CO and oxygen (O) on the surface, allowing the reactants to collide, and, with a transient close to a picosecond (ps), new electronic states appear in the O K-edge x-ray absorption spectrum. Density functional theory calculations indicate that these result from changes in the adsorption site and bond formation between CO and O with a distribution of OC-O bond lengths close to the transition state (TS). After 1 ps, 10% of the CO populate the TS region, which is consistent with predictions based on a quantum oscillator model.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ostrom, H -- Oberg, H -- Xin, H -- LaRue, J -- Beye, M -- Dell'Angela, M -- Gladh, J -- Ng, M L -- Sellberg, J A -- Kaya, S -- Mercurio, G -- Nordlund, D -- Hantschmann, M -- Hieke, F -- Kuhn, D -- Schlotter, W F -- Dakovski, G L -- Turner, J J -- Minitti, M P -- Mitra, A -- Moeller, S P -- Fohlisch, A -- Wolf, M -- Wurth, W -- Persson, M -- Norskov, J K -- Abild-Pedersen, F -- Ogasawara, H -- Pettersson, L G M -- Nilsson, A -- New York, N.Y. -- Science. 2015 Feb 27;347(6225):978-82. doi: 10.1126/science.1261747. Epub 2015 Feb 12.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics, AlbaNova University Center, Stockholm University, SE-10691, Sweden. ; SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA. ; SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA. SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, CA 95305, USA. ; SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA. Helmholtz Zentrum Berlin fur Materialien und Energie GmbH, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany. ; Physics Department and Center for Free Electron Laser Science, University of Hamburg, Luruper Chausse 149, D-22761 Hamburg, Germany. ; Department of Physics, AlbaNova University Center, Stockholm University, SE-10691, Sweden. SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA. ; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA. ; Helmholtz Zentrum Berlin fur Materialien und Energie GmbH, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany. ; Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA. ; Helmholtz Zentrum Berlin fur Materialien und Energie GmbH, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany. Fakultat fur Physik und Astronomie, Universitat Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam, Germany. ; Fritz-Haber Institute of the Max-Planck-Society, Faradayweg 4-6, D-14195 Berlin, Germany. ; Physics Department and Center for Free Electron Laser Science, University of Hamburg, Luruper Chausse 149, D-22761 Hamburg, Germany. Deutsches Elektronen-Synchrotron, Photon Science, Notkestrasse 85, D-22607 Hamburg, Germany. ; Surface Science Research Centre and Department of Chemistry, The University of Liverpool, Liverpool, L69 3BX, UK. ; Department of Physics, AlbaNova University Center, Stockholm University, SE-10691, Sweden. SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA. Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA. nilsson@slac.stanford.edu.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25722407" target="_blank"〉PubMed〈/a〉

Description: The initiation of mRNA degradation often requires deprotection of its 5′ end. In eukaryotes, the 5′-methylguanosine (cap) structure is principally removed by the Nudix family decapping enzyme Dcp2, yielding a 5′-monophosphorylated RNA that is a substrate for 5′ exoribonucleases. In bacteria, the 5′-triphosphate group of primary transcripts is also converted...