Macrocyclic dithiomaleonitriles for an efficient PdCl2 coordination
- We have synthesized a set of new unsaturated macrocyclic dithioethers with an increasing number of flexible methylene units 1-7 (Scheme 2) to investigate the correlation between the ring size of these ligands, the chelation effect and the consequences for an efficient PdCl2 coordination. The dithioethers 1-7 and the complex [PdCl2(4)]center dot CHCl3 were characterized by X-ray diffraction analysis. The crystal structures of 1-7 show that 2-7 are better preorganized chelating ligands for an exocyclic PdCl2 coordination than 1. The chelation effect of 1-7, the orientation of the sulfur atoms and the S center dot center dot center dot S donor distances, are influenced by the flexibility of the methylene units. In this series the unsaturated macrocyclic ligands 5 and 6 are the best chelating ligands for an efficient PdCl2 coordination. Comparative solvent extraction experiments with mn-12S(2)O(2) (mn = maleonitrile) reveal that the low interface activity of the new ligands reduces the extraction rate. However, a comparison withWe have synthesized a set of new unsaturated macrocyclic dithioethers with an increasing number of flexible methylene units 1-7 (Scheme 2) to investigate the correlation between the ring size of these ligands, the chelation effect and the consequences for an efficient PdCl2 coordination. The dithioethers 1-7 and the complex [PdCl2(4)]center dot CHCl3 were characterized by X-ray diffraction analysis. The crystal structures of 1-7 show that 2-7 are better preorganized chelating ligands for an exocyclic PdCl2 coordination than 1. The chelation effect of 1-7, the orientation of the sulfur atoms and the S center dot center dot center dot S donor distances, are influenced by the flexibility of the methylene units. In this series the unsaturated macrocyclic ligands 5 and 6 are the best chelating ligands for an efficient PdCl2 coordination. Comparative solvent extraction experiments with mn-12S(2)O(2) (mn = maleonitrile) reveal that the low interface activity of the new ligands reduces the extraction rate. However, a comparison with open-chain dithiomaleonitriles shows the impact of the macrocyclic effect of 4 and 5 on the extraction yield.…
Author details: | Thomas SchwarzeORCiD, Juliane Traeger, Alexandra Kelling, Uwe SchildeORCiDGND, Hans-Jürgen HoldtORCiD |
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DOI: | https://doi.org/10.1016/j.ica.2013.08.020 |
ISSN: | 0020-1693 |
ISSN: | 1873-3255 |
Title of parent work (English): | Inorganica chimica acta : the international inorganic chemistry journal |
Publisher: | Elsevier |
Place of publishing: | Lausanne |
Publication type: | Article |
Language: | English |
Year of first publication: | 2013 |
Publication year: | 2013 |
Release date: | 2017/03/26 |
Tag: | Chelation effect; Extraction; Palladium; Synthesis; Thioether ligands; X-ray diffraction |
Volume: | 408 |
Issue: | 2 |
Number of pages: | 6 |
First page: | 53 |
Last Page: | 58 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
Peer review: | Referiert |