EPR‐spektroskopische Charakterisierung (X‐, Q‐Band) monomerer AgII‐ und AuII‐Komplexe der Thiakronenether [12]anS4, [16]anS4, [18]anS6 und [27]anS9 |
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Authors: | Michael Kampf Jan Griebel Reinhard Kirmse |
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Abstract: | EPR Spectroscopic Characterization (X‐, Q‐Band) of Monomeric AgII‐ and AuII‐Complexes of the Thiacrownethers [12]aneS4, [16]aneS4, [18]aneS6 and [27]aneS9 The reaction of the prepared AgI complexes of the thiacrownethers [12]aneS4, [16]aneS4, [18]aneS6 and [27]aneS9 with c. H2SO4 as well as the reaction of [AuIIICl4]‐ with [18]aneS6 and [27]aneS9 leads to labile AgII‐ (4d9, 107, 109Ag: I=1/2) and AuII‐ (5d9, 197Au: I=3/2) thiacrownether complexes, respectively, which were characterized by X‐ and Q‐band EPR. The EPR spectra of [AgII([12]anS4)]2+ and [AgII([18]anS6)]2+ were reinvestigated. According to an analysis of the spin‐density distribution only 20 ‐ 25 % is located on the Ag or Au atoms. Most of the spin‐density was found to be on the S donor atoms of the thiacrownethers. The high delocalization of the spin‐density leads certainly to a noticeable reduction of the AgI/AgII redox potential and is considered as being mainly responsible for the easy accessibility of the AgII compounds. |
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Keywords: | Gold Silver Thiacrown ether complexes EPR spectroscopy |
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