17 Result(s)
within
Helmut Schwarz
Physical Chemistry
-
Article
Obituary for Rudolf Zahradník (1928–2020): “To Do What’s Right”
-
Article
Ligand Effects on the Reactivity of [CoX]+ (X = CN, F, Cl, Br, O, OH) Towards CO2: Gas-Phase Generation of the Elusive Cyanoformate by [Co(CN)]+ and [Fe(CN)]+
The thermal reactions of [CoX]+ (X = CN, F, Cl, Br, O, OH) with carbon dioxide have been investigated experimentally and theoretically by using electrospray ionization mass spectrometry (ESI-MS) and density funct...
-
Article
Gas-phase reactions of cationic molybdenum and tungsten monoxide with ethanol: a combined experimental/computational exercise
The ion/molecule reactions of molybdenum and tungsten monoxide cations MO+ (M═Mo, W) with ethanol have been studied by Fourier transform ion-cyclotron resonance mass spectrometry (FT-ICR MS) and density functiona...
-
Article
On the usefulness of useless knowledge
Basic research may or may not lead to new technologies. Our safest bet in this gamble is to give our brightest minds the funding and freedom to dream big.
-
Article
Open AccessEffects of Ligands, Cluster Size, and Charge State in Gas-Phase Catalysis: A Happy Marriage of Experimental and Computational Studies
We present selected examples of gas-phase reactions which are of timely interest for the activation of small molecules. Due to the very nature of the experiments, detailed insight in the active site of catalys...
-
Article
Bonding in cationic MOH n + (M = K − La, Hf − Rn; n = 0–2): DFT performances and periodic trends
The performances of the DFT functionals B3LYP, BHandHLYP, M06, M06-2X, PBE1PBE, TPSSh, X3LYP, and BP86 have been benchmarked with a thermochemistry database containing 50 bond dissociation energies (BDEs) of M–OH
-
Chapter
Diastereoselective Effects in Gas-Phase Ion Chemistry
A method for the investigation of diastereoselective effects in reactions of gaseous ions bearing flexible backbones is described. It relies on the study of diastereoselectively labeled substrates that are stu...
-
Chapter
Characterization, Orbital Description, and Reactivity Patterns of Transition-Metal Oxo Species in the Gas Phase
Metal-oxo and -peroxo species play key roles in catalytic oxidations using transition metals This contribution addresses gas-phase studies of diatomic metal-oxo species and their properties which turn out to b...
-
Article
The singlet and triplet states of phenyl cation. A hybrid approach for locating minimum energy crossing points between non-interacting potential energy surfaces
The phenyl cation is known to have two low-energy minima, corresponding to 1 A 1 and 3 B 1 states, the first of which is more stable by ca. 25 kcal/mol. The minimum energy crossing point between these two surfac...
-
Chapter
The Search For Elusive Potentially Interstellar Neutrals by Neutralization-Reionization Mass Spectrometry: Polycarbon Chalcogenides X(Cn)Y (X, Y: O, S)
Many elusive polycarbon chalcogenides X(Cn)Y (X, Y: O, S; n≥2) having both odd and even-numbered carbon atoms can easily be generated and characterized in the gas phase by electron transfer processes using the te...
-
Chapter
Beam Experiments as a Means for the Generation of Elusive Sulfur-Containing Molecules
Quite a few molecular species can only be generated in the gas phase because in solution or even in the solid state intermolecular interactions will make them unstable and lead to isomerization, polymerization or...
-
Chapter and Conference Paper
Remote Functionalization of Carbon-Hydrogen and Carbon-Carbon Bonds by Bare Transition Metal Ions in the Gas Phase
The selective functionaIization of C-H bonds remains one of the major focuses of catalytic and organic chemistry. High selectivity is often achieved by the presence of activating groups which induce the reacti...
-
Chapter
Experimental and Theoretical Studies of Small Organic Dications, Molecules with Highly Remarkable Properties
Using the results of both, experiments as well as high level quantum chemical calculations the exciting properties of small doubly-charged cations in the gas phase are discussed. The comparison of experimental...
-
Chapter
Carbon Skeletal Rearrangements Via Pyramidal Carbocations
The scrambling of carbon atoms in gaseous carbocations is readily explicable by invoking transition states or intermediates of pyramidal structure, which are now be seen as the logical bridge between organic a...
-
Article
Synthesen von Xyluron- und Riburonsäurederivaten
Various 3-O-acyl-pentofuranurononitrils were synthesized by acylating dehydration of 1,2-isopropylidene-d-xylo- andd-ribo-pentodialdo-furanose oximes, or pentofuranuronic acids via intermediates. Their reactions ...
-
Article
Eliminierungen an Penturon- und Hepturonsäurederivaten
Some previously described derivatives ofd-xyluronic andd-riburonic acid together with newly prepared 6-deoxy-d-gluco-heptofuranuronic acid derivatives are compared in elimination and addition reactions.
-
Article
Reaktionen der Glucuronsäure, 3. Mitt.
Beim Versuch der Gewinnung von 5,6-Didesoxy-5,6-imino-l-ido-furanosiden aus einer Reihe verschieden substituierter 5-O-Mesyl-d-glucofuranosiduronsäurenitrile wurden im Zuge der katalytischen Hydrierung in unvorhe...
