@article{63965, author = {{Gutmann, Torsten and Ratajczyk, Tomasz and Xu, Yeping and Breitzke, Hergen and Gruenberg, Anna and Dillenberger, Sonja and Bommerich, Ute and Trantzschel, Thomas and Bernarding, Johannes and Buntkowsky, Gerd}}, journal = {{Solid State Nuclear Magnetic Resonance}}, number = {{4}}, pages = {{90–96}}, title = {{{Understanding the leaching properties of heterogenized catalysts: A combined solid-state and PHIP NMR study}}}, doi = {{10.1016/j.ssnmr.2011.03.001}}, volume = {{38}}, year = {{2010}}, } @article{64055, abstract = {{A program for iterative fitting procedures to determine the NMR parameters from 51V solid-state MAS NMR spectra was developed. It contains options to use genetic algorithms and downhill-simplex optimizing procedures to extract the optimal parameter sets, which describe our spectra. As computational kernel the SIMPSON program is employed. Other kernels like SPINEVOLUTION are easily incorporable. The algorithms are checked for their suitability for the present optimization problem and optimal simulation conditions are determined, with the focus on minimal processing time. The procedure leads to a very good agreement between experimental and simulated spectra in a passable period of time. First results for spectra of model compounds for the active site of vanadium haloperoxidases are presented.}}, author = {{Waechtler, Maria and Schweitzer, Annika and Gutmann, Torsten and Breitzke, Hergen and Buntkowsky, Gerd}}, journal = {{Solid State Nuclear Magnetic Resonance}}, keywords = {{51V MAS NMR spectroscopy, Genetic algorithms, Iterative fitting procedures, Model complexes for vanadium haloperoxidases}}, number = {{1}}, pages = {{37–48}}, title = {{{Efficient analysis of 51V solid-state MAS NMR spectra using genetic algorithms}}}, doi = {{10.1016/j.ssnmr.2008.11.003}}, volume = {{35}}, year = {{2009}}, } @article{63967, author = {{Gutmann, Torsten and Sellin, Martin and Breitzke, Hergen and Stark, Annegret and Buntkowsky, Gerd}}, journal = {{Physical Chemistry Chemical Physics}}, number = {{40}}, pages = {{9170–9175}}, title = {{{Para-hydrogen induced polarization in homogeneous phase-an example of how ionic liquids affect homogenization and thus activation of catalysts}}}, doi = {{10.1039/b908198d}}, volume = {{11}}, year = {{2009}}, } @article{63951, abstract = {{The parameters describing the quadrupolar and CSA interactions of 51V solid-state MAS NMR investigations of model complexes mimicking vanadoenzymes as well as vanadium containing catalysts and enzyme complexes are interpreted with respect to the chemical structure. The interpretation is based on the data of 15 vanadium complexes including two new complexes with previously unpublished data and 13 complexes with data previously published by us. Correlations between the chemical structure and the 51V solid-state NMR data of this class of compounds have been established. Especially for the isotropic chemical shift δ iso and the chemical shift anisotropy δ σ , correlations with specific structural features like the coordination number of the vanadium atom, the number of coordinating nitrogens, the number of oxygen atoms and the chemical surrounding of the complex could be established for these compounds. Moreover, quantitative correlations between the solid-state NMR parameters and specific bond angles and bond lengths have been obtained. Our results can be of particular interest for future investigations concerning the structure and the mode of action of related vanadoenzymes and vanadate protein assemblies, including the use of vanadate adducts as transition state analogs for phosphate metabolizing systems.}}, author = {{Fenn, Annika and Wächtler, Maria and Gutmann, Torsten and Breitzke, Hergen and Buchholz, Axel and Lippold, Ines and Plass, Winfried and Buntkowsky, Gerd}}, journal = {{Solid State Nuclear Magnetic Resonance}}, keywords = {{51V NMR, Cis-dioxovanadium (v) complex, Model system, Vanadate}}, number = {{4}}, pages = {{192–201}}, title = {{{Correlations between 51V solid-state NMR parameters and chemical structure of vanadium (V) complexes as models for related metalloproteins and catalysts}}}, doi = {{10.1016/j.ssnmr.2009.11.003}}, volume = {{36}}, year = {{2009}}, } @article{63941, author = {{Del Rosal, Iker and Gutmann, Torsten and Maron, Laurent and Jolibois, Franck and Chaudret, Bruno and Walaszek, Bernadeta and Limbach, Hans-Heinrich and Poteau, Romuald and Buntkowsky, Gerd}}, journal = {{Physical Chemistry Chemical Physics}}, number = {{27}}, pages = {{5657–5663}}, title = {{{DFT (2)H quadrupolar coupling constants of ruthenium complexes: a good probe of the coordination of hydrides in conjuction with experiments}}}, doi = {{10.1039/b822150b}}, volume = {{11}}, year = {{2009}}, } @article{64056, author = {{Walaszek, Bernadeta and Adamczyk, Anna and Pery, Tal and Xu, Yeping and Gutmann, Torsten and Amadeu, Nader de Sousa and Ulrich, Stefan and Breitzke, Hergen and Vieth, Hans Martin and Sabo-Etienne, Sylviane and Chaudret, Bruno and Limbach, Hans-Heinrich and Buntkowsky, Gerd}}, journal = {{Journal of the American Chemical Society}}, number = {{51}}, pages = {{17502–17508}}, title = {{{H-2 Solid-State NMR of Ruthenium Complexes}}}, doi = {{10.1021/ja806344y}}, volume = {{130}}, year = {{2008}}, } @article{64041, abstract = {{Three cis-dioxovanadium(V) complexes with similar N -salicylidenehydrazide ligands modeling hydrogen bonding interactions of vanadate relevant for vanadium haloperoxidases are studied by 51V solid-state NMR spectroscopy. Their parameters describing the quadrupolar and chemical shift anisotropy interactions (quadrupolar coupling constant C Q , asymmetry of the quadrupolar tensor η Q , isotropic chemical shift δ iso , chemical shift anisotropy δ σ , asymmetry of the chemical shift tensor η σ and the Euler angles α , β and γ ) are determined both experimentally and theoretically using DFT methods. A comparative study of different methods to determine the NMR parameters by numerical simulation of the spectra is presented. Detailed theoretical investigations on the DFT level using various basis sets and structural models show that by useful choice of the methodology, the calculated parameters agree to the experimental ones in a very good manner.}}, author = {{Schweitzer, Annika and Gutmann, Torsten and Wächtler, Maria and Breitzke, Hergen and Buchholz, Axel and Plass, Winfried and Buntkowsky, Gerd}}, journal = {{Solid State Nuclear Magnetic Resonance}}, keywords = {{51V NMR, Model system, Ab initio calculation, Cis-dioxovanadium(V) complex, Haloperoxidase, Numerical optimization, Quadrupolar interaction}}, number = {{1–2}}, pages = {{52–67}}, title = {{{51V solid-state NMR investigations and DFT studies of model compounds for vanadium haloperoxidases}}}, doi = {{10.1016/j.ssnmr.2008.02.003}}, volume = {{34}}, year = {{2008}}, } @article{63966, author = {{Gutmann, Torsten and Schweitzer, Annika and Waechtler, Maria and Breitzke, Hergen and Buchholz, Axel and Plass, Winfried and Buntkowsky, Gerd}}, issn = {{0942-9352}}, journal = {{Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics}}, number = {{8-9}}, pages = {{1389–1406}}, title = {{{DFT Calculations of (51)V Solid-State NMR Parameters of Vanadium(V) Model Complexes}}}, doi = {{10.1524/zpch.2008.5401}}, volume = {{222}}, year = {{2008}}, } @article{63933, author = {{Buntkowsky, G. and Limbach, H. H. and Walaszek, B. and Adamczyk, A. and Xu, Y. and Breitzke, H. and Schweitzer, A. and Gutmann, Torsten and Waechtler, M. and Frydel, J. and Elnmler, Th and Amadeu, N. and Tietze, D. and Chaudret, B.}}, issn = {{0942-9352}}, journal = {{Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics}}, number = {{7}}, pages = {{1049–1063}}, title = {{{Mechanisms of dipolar ortho/para-H2O conversion in ice}}}, doi = {{10.1524/zpch.2008.5359}}, volume = {{222}}, year = {{2008}}, }