@article{BaierKellingSchildeetal.2016,
  author    = {Baier, Heiko and Kelling, Alexandra and Schilde, Uwe and Holdt, Hans-J{\"u}rgen},
  title     = {Investigation of the Catalytic Activity of a 2-Phenylidenepyridine Palladium(II) Complex Bearing 4,5-Dicyano-1,3-bis(mesityl)imidazol-2-ylidene in the Mizoroki-Heck Reaction},
  series = {Zeitschrift f{\~A}¼r anorganische und allgemeine Chemie},
  volume    = {642},
  journal   = {Zeitschrift f{\~A}¼r anorganische und allgemeine Chemie},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0044-2313},
  doi       = {10.1002/zaac.201500625},
  pages     = {140 -- 147},
  year      = {2016},
  abstract  = {The phenylidenepyridine (ppy) palladacycles [PdCl(ppy)(IMes)] (4) [IMes = 1,3-bis(mesityl) imidazol-2-ylidene] and [PdCl(ppy){(CN)(2)IMes}] (6) [(CN)(2)IMes = 4,5-dicyano-1,3-bis(mesityl) imidazol-2-ylidene] were prepared by facile two step syntheses, starting with the reaction of palladium(II) chloride with 2-phenylpyridine followed by subsequent addition of the NHC ligand to the precatalyst precursor [PdCl(ppy)](2). Suitable crystals for the X-ray analysis of the complexes 4 and 6 were obtained. It was shown that 6 has a shorter NHC-palladium bond than the IMes complex 4. The difference of the palladium carbene bond lengths based on the higher pi-acceptor strength of (CN)(2)IMes in comparison to IMes. Thus, (CN)(2)IMes should stabilize the catalytically active central palladium atom better than IMes. As a measure for the pi-acceptor strength of (CN)(2)IMes compared to IMes, the selone (CN)(2)IMes center dot Se (7) was prepared and characterized by Se-77-NMR spectroscopy. The pi-acceptor strength of 7 was illuminated by the shift of its Se-77-NMR signal. The Se-77-NMR signal of 7 was shifted to much higher frequencies than the Se-77-NMR signal of IMes center dot Se. Catalytic experiments using the Mizoroki-Heck reaction of aryl chlorides with n-butyl acrylate showed that 6 is the superior performer in comparison to 4. Using complex 6, an extensive substrate screening of 26 different aryl bromides with n-butyl acrylate was performed. Complex 6 is a suitable precatalyst for para-substituted aryl bromides. The catalytically active species was identified by mercury poisoning experiments to be palladium nanoparticles.},
  language  = {en}
}
@misc{BornhorstKippHaaseetal.2018,
  author    = {Bornhorst, Julia and Kipp, Anna Patricia and Haase, Hajo and Meyer, Soeren and Schwerdtle, Tanja},
  title     = {The crux of inept biomarkers for risks and benefits of trace elements},
  series = {Trends in Analytical Chemistry},
  volume    = {104},
  journal   = {Trends in Analytical Chemistry},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0165-9936},
  doi       = {10.1016/j.trac.2017.11.007},
  pages     = {183 -- 190},
  year      = {2018},
  abstract  = {Nowadays, the role of trace elements (TE) is of growing interest because dyshomeostasis of selenium (Se), manganese (Mn), zinc (Zn), and copper (Cu) is supposed to be a risk factor for several diseases. Thereby, research focuses on identifying new biomarkers for the TE status to allow for a more reliable description of the individual TE and health status. This review mirrors a lack of well-defined, sensitive, and selective biomarkers and summarizes technical limitations to measure them. Thus, the capacity to assess the relationship between dietary TE intake, homeostasis, and health is restricted, which would otherwise provide the basis to define adequate intake levels of single TE in both healthy and diseased humans. Besides that, our knowledge is even more limited with respect to the real life situation of combined TE intake and putative interactions between single TE.},
  language  = {en}
}