3 years ago

Charge density studies of 3d metal (Ni/Cu) complexes with a non-innocent ligand

Charge density studies of 3d metal (Ni/Cu) complexes with a non-innocent ligand
Yu Wang, Chou-Fu Sheu, Yu-Chun Chuang, Gene-Hsiang Lee, Yu-Sheng Chen
High-resolution X-ray diffraction experiments and atom-specific X-ray absorption experiments are applied to investigate a series of square planar complexes with the non-innocent ligand of maleonitriledithiolate (mnt), [S2C2(CN)2]z−, containing M—S bonds. Four complexes of (PyH)z[M(mnt)2]z−, where M = Ni or Cu, z = 2 or 1 and PyH+ = C5NH6+, were studied in order to clarify whether such one-electron oxidation–reduction, [M(mnt)2]2−/[M(mnt)2]1−, is taking place at the metal or the ligand site. Combining the techniques of metal K-, L-edge and S K-edge X-ray absorption spectroscopy with high-resolution X-ray charge density studies, it is unambiguously demonstrated that the electron redox reaction is ligand based and metal based for Ni and Cu pairs, respectively. The bonding characters in terms of topological properties associated with the bond critical points are compared between the oxidized form [ML]− and the reduced form [ML]2−. In the case of Ni complexes, the formal oxidation state of Ni remains as Ni2+ and each mnt ligand carries a 2− charge in [Ni(mnt)2]2−, but only one of the ligands is formally oxidized in [Ni(mnt)2]1−. In contrast, in the case of Cu complexes, the mnt remains as 2− in both complexes, but the formal oxidation states of the metal are Cu2+ and Cu3+. Bond characterizations and d-orbital populations will be presented. The complementary results of XAS, XRD and DFT calculations will be discussed. The conclusion on the redox reactions in these complexes can be firmly established.The redox characteristics of pairs of square planar complexes M(mnt)22−/M(mnt)2−, where mnt is the non-innocent maleonitriledithiolate ligand, are established through charge density analysis and X-ray absorption spectroscopy: the oxidation is ligand based in Ni complexes and are metal based for the Cu case.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1107/S2052520617007119

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.