Inst. Chemie

666 Items

Recent Submissions
Response to “Comment on ‘Indications of energetic consequences of decoherence at short times for scattering from open quantum systems’” [AIP Advances 1, 049101 (2011)]

Chatzidimitriou-Dreismann, Chariton Aris ; Gray, E. MacA. ; Blach, T. P. (2011)

The Comment by Mayers and Reiter criticizes our work on two counts. Firstly, it is claimed that the quantum decoherence effects that we report in consequence of our experimental analysis of neutron Compton scattering from H in gaseous H2 are not, as we maintain, outside the framework of conventional neutron scattering theory. Secondly, it is claimed that we did not really observe such effects, ...

Synthesis of an electronically modified carbon nitride from a processable semiconductor, 3-amino-1,2,4-triazole oligomer, via a topotactic-like phase transition

Savateev, Aleksandr ; Pronkin, Sergey ; Epping, Jan Dirk ; Willinger, Marc Georg ; Antonietti, Markus ; Dontsova, Dariya (2017)

A thermally induced topotactic transformation of organic polymeric semiconductors is achieved using similarity of the chemical structures of two C,N,H-containing materials. Namely, the oligomer of 3-amino-1,2,4-triazole (OATA) is transformed into an electronically modified graphitic carbon nitride (OATA-CN) upon heating at 550 °C. During the transition, the flat band potential of the organic se...

Cyclohexa-1,4-dienes in transition-metal-free ionic transfer processes

Keess, Sebastian ; Oestreich, Martin (2017)

Safe- and convenient-to-handle surrogates of hazardous chemicals are always in demand. Recently introduced cyclohexa-1,4-dienes with adequate substitution fulfil this role as El+/H− equivalents in B(C6F5)3-catalysed transfer reactions of El–H to π- and σ-donors (C[double bond, length as m-dash]C/C[triple bond, length as m-dash]C and C[double bond, length as m-dash]O/C[double bond, length as m-d...

Synthesis of a cyclopentadienyl(imino)stannylene and its direct conversion into halo(imino)stannylenes

Ochiai, Tatsumi ; Inoue, Shigeyoshi (2017)

The reaction of stannocene Cp2Sn with iminolithium LiNIPr (NIPr = bis(2,6-diisopropylphenyl)imidazolin-2-iminato) afforded the dimeric cyclopentadienyl(imino)stannylene [(η1-Cp)SnNIPr]2 (1). Compound 1 exhibits unexpected reactivity towards haloalkanes. The high-yield conversion of 1 into chlorostannylene [ClSnNIPr]2 (2) and bromostannylene [BrSnNIPr]2 (3) were accomplished by treatment with di...

Construction of a polyproline structure with hydrophobic exterior using octahydroindole-2-carboxylic acid

Kubyshkin, Vladimir ; Budisa, Nediljko (2016)

The proline analogue (2S,3aS,7aS)-octahydroindole-2-carboxylic acid (Oic) has been previously applied as a proline substitute in pharmocologically active peptides and as a structural component of the antihypertensive drug Perindopril. Herein, we describe the formation of an oligoproline structure by an Oic oligomer. A series of Oic oligomers were investigated to show the structural and energeti...

PNIPAM microgels in external fields

Backes, Sebastian (2018)

Poly(N-isopropylacrylamide) (PNIPAM) microgels respond to changes in temperature by shrinking in aqueous solution above their volume phase transition temperature (VPTT). Additionally, they shrink in mixtures of water and ethanol, although both individual liquids are good solvents. This is termed cononsolvency. Combined DLS experiments and MD simulations show that microgels in aqueous alcohol bu...

Rhodium-catalysed hydroformylation of long-chain alkenes in aqueous multiphase systems: Kinetic studies and systematic process development

Pogrzeba, Tobias (2018)

In the course of the development of new sustainable industrial chemical processes the exploitation of switchable solvent systems is increasingly investigated in various fields. The application of highly efficient catalysts and safer solvents is mandatory to make a step towards a greener chemistry, as well as to find innovative ways to reduce waste from chemical reactions. Consequently, the use ...

Structural examination of hydrophobic tunnels in proteins

Kalms, Jacqueline (2018)

Enzymes are the biological macromolecular catalysts of life, which work with high substrate specificity, under fine-tuned conditions compared to chemical catalysts. The majority of the catalytic centres of enzymes are located deeply within the protein matrix. To provide efficient substrate accessibility to the active site most proteins offer permanent or transient tunnels as transport pathways....

Protein adsorption on nanostructured silica surfaces

Meißner, Jens (2018)

This Ph.D. thesis presents a study of the interaction of globular proteins with nanostructured silica surfaces. It aims to gain a better understanding of the consequences of a high surface curvature and confinement on the adsorption behavior and morphology of the adsorbed protein. The adsorption behavior of lysozyme and 𝛽-lactoglobulin on silica nanoparticles was studied from pH 2 to 11 and ...

Bioinspired solid catalysts for the hydroxylation of methane

Le, Ha Vu (2018)

Abundant and cheap resources including natural gas, methane hydrates, and biogas, whose major component is methane, have been considered as promising alternatives to decline the dependence of chemical and energy industries on crude oil. However, there is currently an underutilization of these resources, especially due to the costly transportation and storage, and high chemical inertness of meth...

Supported liquid phase catalysts

Ahi, Hamideh (2018)

This thesis deals with the investigation of silica-supported vanadia-based Supported Liquid Phase (SLP) catalysts in Oxidative Dehydrogenation of Propane (ODP). The aim is a better understanding of the structural requirements of oxidation catalysts. The approach is based on the observation that high-performance catalysts in selective oxidation exhibit a thin surface layer, which is chemically a...

Gas-phase activation of CO2 and CH4 by selected transition-metal complexes: ligand effects and the role of the metal

Firouzbakht, Marjan (2018)

Die vorliegende Arbeit behandelt die Übergangsmetall-vermittelten Aktivierungen von CO2 und CH4, die mittels massenspektrometrischer Methoden und quantenchemischer Rechnungen untersucht wurden. Die Kationen der jeweiligen Übergangsmetalle wurden durch Elektrosprayionisation (ESI) erzeugt und anschließend mit der Tandem-Massenspektrometrie unter Quadrupol-Hexapol-Quadrupol Anordnung charakterisi...

Kooperative Si–H-Bindungsaktivierung an einem Ru–S-Komplex mit axial chiralem Rückgrat

Wübbolt, Simon (2018)

Die vorliegende Dissertation widmet sich der simultanen Erzeugung von Siliciumelektrophilen und den entsprechenden Metallhydriden für die asymmetrische Katalyse durch kooperative Si–H-Bindungsaktivierung entlang einer Ruthenium–Schwefel-Bindung. Mit Hilfe heterolytischer Si–H-Bindungsspaltung mit Rutheniumthiolatkomplexen können Hydrosilane in ein schwefelstabilsiertes Silyliumion und ein Ruth...

Fully relativistic calculations of EPR and paramagnetic NMR parameters for heavy atom compounds

Gohr, Sebastian (2018)

In the thesis at hand, a 4-component relativistic density functional theory (DFT) approach is applied within the ReSpect program package to calculations of magnetic resonance parameters for various open-shell systems containing heavy 4d and 5d transition metals. Such calculations represent a relatively uncharted territory. Therefore, the present work starts with a comprehensive benchmark study ...

Stereodivergente ionische und radikalische Silylzinkierungen von α-heteroatomsubstituierten C–C-Dreifachbindungen

Fopp, Carolin (2018)

The present work investigates the stereodivergent silylzincation of α-heteroatom-substituted C–C triple bonds. In close collaboration with the group of PEREZ-LUNA, α-nitrogen-, α-phosphor-, α-oxygen-, and α-sulfur-substituted terminal alkynes were reacted with (Me3Si)3SiH/Et2Zn or [(Me3Si)3Si]2Zn/Et2Zn as well as (Me2PhSi)2Zn∙4LiCl. The addition of these reagents to the C–C triple bonds general...

Comparative venomics of the Vipera ammodytes transcaucasiana and Vipera ammodytes montandoni from Turkey provides insights into kinship

Hempel, Benjamin-Florian ; Damm, Maik ; Göçmen, Bayram ; Karis, Mert ; Oguz, Mehmet Anıl ; Nalbantsoy, Ayse ; Süssmuth, Roderich D. (2018)

The Nose-horned Viper (Vipera ammodytes) is one of the most widespread and venomous snakes in Europe, which causes high frequent snakebite accidents. The first comprehensive venom characterization of the regional endemic Transcaucasian Nose-horned Viper (Vipera ammodytes transcaucasiana) and the Transdanubian Sand Viper (Vipera ammodytes montandoni) is reported employing a combination of intact...

IR spectro-electrochemistry of an adsorbed oxygen-tolerant [NiFe] hydrogenase on conductive surfaces

Heidary, Nina (2017)

Hydrogenases are metalloenzymes, catalyzing the reversible oxidation of molecular hydrogen into two protons and two electrons. The 'Knallgasbacterium' Ralstonia eutropha H16 (Re) is one of the few examples, harboring several [NiFe] hydrogenases that established mechanisms to enable catalytic conversion of H2 in the presence of O2. In order to exploit the catalytic potential of these oxygen-tole...

Beiträge zur bioinspirierten Katalyse

Lindenmaier, Nils (2017)

In dieser Arbeit wurden einkernige Ni- und heterodimere [NiFe]-Komplexe im Kontext der von [NiFe]-H2ase und -CODH „bioinspirierten” Katalyse synthetisiert und untersucht. Im ersten Teil der Arbeit wurde ein neuartiger Silylen-Pyridin-Hybridligand für die Koordination von Nickel(II)- und Nickel(0)-Spezies entwickelt und auf seine σ-Donor- und π-Akzeptoreigenschaften hin analysiert. Der zweite Te...

Scattering techniques for nanoparticle analysis

Breßler, Ingo (2017)

This work presents three program packages implementing different methods for nanoparticle analysis, focusing on the quantitative determination of particle size distributions required in standardization of nanoparticle reference materials. In part one, classical curve fitting is discussed. It finds optimal parameters of a scattering model composed of analytical expressions. The classical curve ...

Multinary metal oxides for solar water splitting

Wang, Fuxian (2017)

The world has experienced an exponential increase in the demand for energy primarily coming from the consumption of fossil fuels, which is accompanied by the inevitable emission of carbon dioxide, causing global warming. Developing renewable and carbon-free sources is essential to reduce carbon dioxide emission and mitigate global warming. Among the renewable energy sources, solar energy has th...