Einar Uggerud

• Platania, Elena; Caruso, Francesco; Nevin, Austin; Vila, Anna; Buti, David & Uggerud, Einar (2025). Transformations of Late Medieval Church Art: The Role and Challenges of Conservation Science. In Streeton, Noëlle Lynn Wenger; Frøysaker, Tine & Bjerregaard, Peter (Ed.), Sacred Medieval Objects and Their Afterlives in Scandinavia. De Gruyter Brill. ISSN 9789004707573. p. 321–358. doi: 10.1163/9789004712034_011. Full text in Research Archive Show summary

  Interconnected investigations between conservators, historians, heritage scientists and museum professionals centre on objects that were essential to medieval Christianity in Scandinavia (c. 1100‒1530). Through new and diverse physical data from polychrome sculptures, shrines, winged altarpieces and painted banners, the authors probe a range of issues and problems, from original devotional functions and changing appearances, to the impacts of changing liturgies, locations and priorities. This book highlights the diversity of theoretical and practical approaches to sacred medieval religious objects, and brings together new findings related to the transformations of these objects since the Reformations.

• Løyland, Sverre & Uggerud, Einar (2024). Competing Reaction Pathways in Gas-Phase Oxidation of C<inf>6</inf>H<inf>6</inf> by Protonated H<inf>2</inf>O<inf>2</inf>. Journal of Physical Chemistry A. ISSN 1089-5639. 128(49), p. 10465–10473. doi: 10.1021/acs.jpca.4c03722. Full text in Research Archive Show summary

  Reactions between protonated hydrogen peroxide and benzene (and benzene-d6) have been studied in the gas phase using an FT-ICR mass spectrometer. Four competing paths for the bimolecular system were identified, namely, proton transfer, hydride abstraction, dissociative single-electron transfer, and an electrophilic addition of HO+ to give the Wheland intermediate [C6H6, OH]+ followed by a subsequent elimination of water. The three latter pathways correspond to three different ways to oxidize benzene. All reaction mechanisms have been modeled using quantum chemical methods, and the calculations are in agreement with the experimental observations. The total reaction rate proceeds at collision rate (slightly higher than the calculated Langevin capture rate), which exemplifies the high reactivity of H3O2+ toward arenes. These observations demonstrate a much richer chemical landscape than previously inferred from the corresponding condensed phase reaction, where only electrophilic substitution by solvated HO+ was described.

• Gjermestad, Christian Sant; Ryding, Mauritz Johan Olof & Uggerud, Einar (2023). Gas phase models of hydride transfer from divalent alkaline earth metals to CO<inf>2</inf> and CH<inf>2</inf>O. Physical Chemistry, Chemical Physics - PCCP. ISSN 1463-9076. 2023(25), p. 16065–16076. doi: 10.1039/d2cp05964a. Full text in Research Archive Show summary

  The reactivity of HMg+, HMgCl, and HMgCl2− in hydride transfer reactions with CO2 and CH2O were studied by means of the reverse reactions—decarboxylation of HCO2MgCln+/0/− and deformylation of CH3OMgCln+/0/− (n = 0–2)—by a combination of quantum chemical computations and mass spectrometry experiments. HCO2Mg+, HCO2MgCl and HCO2MgCl2− display similar energetics for unimolecular carbon dioxide loss; for CH3OMg+, CH3OMgCl and CH3OMgCl2−, formaldehyde loss is more favourable for the cationic species than for the anionic one, with the neutral species found in-between. Despite very similar overall thermochemistry for each of the charge states of the CO2 and CH2O systems, the intermediate reaction barriers are higher for the CO2 eliminations due to a more complex and demanding reaction mechanism. Exothermic ligand exchange is observed for CH3OMg+ reacting with CO2, forming HCO2Mg+ and CH2O. Both the thermochemistry and the presence of intermediate energy barriers slightly disfavour this type of ligand exchange for CH3OMgCl and CH3OMgCl2−. It was also found that CH3OMg+ reacts readily with H2O to eliminate H2, whereas quantum chemical computations predict that the corresponding neutral and anionic species suffer unfavourable reaction thermochemistry. A corresponding reaction for the magnesium formate compounds was not observed. Quantum chemical computations were performed to investigate periodic trends in reactivity. The energetic requirements for decarboxylation of HCO2M+, HCO2MCl and HCO2MCl2− increase in the order M = Be, Mg, Ca, Sr and Ba; the only exception is the cationic Be species for which the reaction is more endothermic than for the corresponding Mg species. For deformylation of CH3OM+, CH3OMCl and CH3OMCl2− the trends are more irregular and less pronounced than for the decarboxylation reactions; however, the Be species was found to have higher reaction energies than the Mg species for all the methoxy-compounds irrespective of charge state. The effect on decarboxylation and deformylation upon replacing Cl with F, Br or I was found to be minimal for all aforementioned species. The consequences of these observations on the reverse reactions, hydride transfer to CO2 and CH2O, are discussed, and the effects of systematic structural changes on reactivity are rationalized on the basis of thermochemical cycles and well-known periodic trends.

• Qureishy, Thomas; Løyland, Sverre; Jørgensen, Susanne Jøntvedt; Færgestad, Eline Mosleth; Norby, Truls & Uggerud, Einar (2022). Mechanisms for sonochemical oxidation of nitrogen. Physical Chemistry, Chemical Physics - PCCP. ISSN 1463-9076. 24(25), p. 15357–15364. doi: 10.1039/d2cp01995g. Full text in Research Archive Show summary

  N2O, and mixtures of N2 and O2, dissolved in water—both in the presence and absence of added noble gases—have been subjected to ultrasonication with quantification of nitrite and nitrate products. Significant increase in product formation upon adding noble gas for both reactant systems is observed, with the reactivity order Ne < Ar < Kr < Xe. These observations lend support to the idea that extraordinarily high electronic and vibrational temperatures arise under these conditions. This is based on recent observations of sonoluminescence in the presence of noble gases and is inconsistent with the classical picture of adiabatic bubble collapse upon acoustic cavitation. The reaction mechanisms of the first few reaction steps necessary for the critical formation of NO are discussed, illustrated by quantum chemical calculations. The role of intermediate N2O in this series of elementary steps is also discussed to better understand the difference between the two reactant sources (N2O and 2 : 1 N2 : O2; same stoichiometry).

• Perrin, Charles L.; Agranat, Israel; Bagno, Alessandro; Braslavsky, Silvia E.; Fernandes, Pedro Alexandrino & Gal, Jean-François [Show all 18 contributors for this article] (2022). Glossary of terms used in physical organic chemistry (IUPAC Recommendations 2021). Pure and Applied Chemistry. ISSN 0033-4545. 94(4), p. 353–534. doi: 10.1515/pac-2018-1010. Full text in Research Archive Show summary

  Abstract This Glossary contains definitions, explanatory notes, and sources for terms used in physical organic chemistry. Its aim is to provide guidance on the terminology of physical organic chemistry, with a view to achieving a consensus on the meaning and applicability of useful terms and the abandonment of unsatisfactory ones. Owing to the substantial progress in the field, this 2021 revision of the Glossary is much expanded relative to the previous edition, and it includes terms from cognate fields.

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• Løyland, Sverre & Uggerud, Einar (2023). Mechanistic insight into the industrial production of H₂O₂ using mass spectrometry. Full text in Research Archive Show summary

  The anthraquinone process is an industrial, catalytic process for the production of hydrogen peroxide, H₂O₂, from hydrogen and oxygen gas. First, an anthraquinone, 1, is catalytically hydrogenated with palladium and hydrogen gas to form an anthrahydroquinone, 2. The reduced molecule 2 is subsequently oxidized back to 1 by spontaneous reaction with oxygen gas, and in the process forming H₂O₂. Although more than 4 million tons of H₂O₂ are produced yearly, the reaction mechanism for the formation of H₂O₂ from 2 is not understood in detail, and the mechanisms presented in most textbooks are probably wrong as they are spin-forbidden. We have performed reactions between a cationic derivative of 2 and O2 gas in the collision cell of a mass spectrometer in conjunction with quantum chemical computations to elucidate the mechanism. As the samples of 2 react with atmospheric oxygen in seconds, the experiments also present some challenging practical aspects of mass spectrometric analyses of reactive molecules.

• Roberts, Aubrey Jane; Görbitz, Carl Henrik; Mossige, Joachim; Samset, Bjørn Hallvard & Uggerud, Einar (2023). Abels Tårn. [Radio]. NRK P3 EKKO. Full text in Research Archive
• Norby, Truls; Ma, Quanbao; Qureishy, Thomas & Uggerud, Einar (2022). Plasma-enhanced ammonia synthesis over nanoscopic Ru/CeO2. Full text in Research Archive
• Jemterud, Torkild; Sverdrup-Thygeson, Anne; Uggerud, Einar; Einevoll, Gaute; Joner, Erik & Skogvoll, Vidar [Show all 7 contributors for this article] (2022). Abels tårn - Suicidale fluer og en ode til urin. Full text in Research Archive
• Jestilä, Joakim Samuel & Uggerud, Einar (2021). An investigation of reductive CO2 activation using tandem mass spectrometric techniques. Full text in Research Archive

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