TY  - GEN
A1  - Kashkarov, Egor B.
A1  - Obrosov, Aleksei
A1  - Sutygina, Alina N.
A1  - Uludintceva, Elena
A1  - Mitrofanov, Andrei
A1  - Weiß, Sabine
T1  - Hydrogen permeation, and mechanical and tribological behavior, of CrNx coatings deposited at various bias voltages on IN718 by direct current reactive sputtering
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - In the current work, the microstructure, hydrogen permeability, and properties of chromium nitride (CrNx) thin films deposited on the Inconel 718 superalloy using direct current reactive sputtering are investigated. The influence of the substrate bias voltage on the crystal structure, mechanical, and tribological properties before and after hydrogen exposure was studied. It was found that increasing the substrate bias voltage leads to densification of the coating. X-ray diffraction (XRD) results reveal a change from mixed fcc-CrN + hcp-Cr2N to the approximately stoichiometric hcp-Cr2N phase with increasing substrate bias confirmed by wavelength-dispersive X-ray spectroscopy (WDS). The texture coefficients of (113), (110), and (111) planes vary significantly with increasing substrate bias voltage. The hydrogen permeability was measured by gas-phase hydrogenation. The CrN coating deposited at 60 V with mixed c-CrN and (113) textured hcp-Cr2N phases exhibits the lowest hydrogen absorption at 873 K. It is suggested that the crystal orientation is only one parameter influencing the permeation resistance of the CrNx coating together with the film structure, the presence of mixing phases, and the packing density of the structure. After hydrogenation, the hardness increased for all coatings, which could be related to the formation of a Cr2O3 oxide film on the surface, as well as the defect formation after hydrogen loading. Tribological tests reveal that hydrogenation leads to a decrease of the friction coefficient by up to 40%. The lowest value of 0.25 +/- 0.02 was reached for the CrNx coating deposited at 60 V after hydrogenation.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1017 
KW  - CrNx coatings
KW  - Physical Vapour Deposition (PVD)
KW  - hydrogenation
KW  - Tribology
KW  - mechanical properties
KW  - X-ray diffraction
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459846
SN  - 1866-8372
IS  - 1017
ER  - 
TY  - JOUR
A1  - Schmidt, Bernd
A1  - Staude, Lucia
T1  - Unexpected transfer hydrogenation of C-C-double bonds during Tandem-RCM-isomerization reactions
JF  - Journal of organometallic chemistry
N2  - Unexpected hydrogen transfer from 2-propanol to C-C-double bonds has been observed in the course of a Tandem RCM-isomerization reaction leading to sterically congested spirocycles.
KW  - ruthenium
KW  - metathesis
KW  - isomerization
KW  - hydrogenation
KW  - transferhydrogenation
KW  - tandem sequence
Y1  - 2006
U6  - https://doi.org/10.1016/j.jorganchem.2006.07.011
SN  - 0022-328X
VL  - 691
IS  - 24-25
SP  - 5218
EP  - 5221
PB  - Elsevier
CY  - Lausanne
ER  - 
TY  - GEN
A1  - Steeples, Elliot
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
A1  - Esposito, Davide
T1  - Amino acid-derived N-heterocyclic carbene palladium complexes for aqueous phase Suzuki–Miyaura couplings
N2  - In this work, three ligands produced from amino acids were synthesized and used to produce five bis- and PEPPSI-type palladium–NHC complexes using a novel synthesis route from sustainable starting materials. Three of these complexes were used as precatalysts in the aqueous-phase Suzuki–Miyaura coupling of various substrates displaying high activity. TEM and mercury poisoning experiments provide evidence for Pd-nanoparticle formation stabilized in water.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 319 
KW  - transition-metal-complexes
KW  - imidazolium salts
KW  - green chemistry
KW  - water
KW  - catalysts
KW  - nhc
KW  - hydrogenation
KW  - isomerization
KW  - nanoparticles
KW  - precatalysts
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-394488
SP  - 4922
EP  - 4930
ER  -