Copper‐Azide‐Thioarylazoimidazoles – Structure, Spectra, Redox Properties, Magnetism and Theoretical Interpretation

Abstract

Abstract Azido‐copper(II) and ‐copper(I) complexes of 1‐alkyl‐2‐[( o ‐thioalkyl)phenylazo]imidazole (SRaaiNR′) have been prepared and studied. Complex 2 [Cu(SRaaiNR′)(μ 1,1 ‐N 3 )(N 3 )] 2 dimerises via end‐to‐end (μ 1,3 )‐N 3 to form a tetrameric structure. Azido‐copper(I) complexes of the ligands are obtained as MeOH‐bridged dimers, [Cu(SRaaiNR′)(N 3 )(μ‐OHMe)] 2 ( 3 ). The electronic spectra suggest that a small reorganisation energy (0.08 eV) is associated with the change in electronic configuration, structure and oxidation state from Cu II to Cu I . Redox interconversion, Cu II ↔ Cu I , [Cu(SMeaaiNMe)(μ‐N 3 )(N 3 )] 2 ( 2a ) ↔ [Cu(SMeaaiNMe)(N 3 )(μ‐OHCH 3 )] 2 ( 3a ), has been performed in one case. The tetranuclear complex shows ferromagnetic and antiferromagnetic interactions. The spectra, redox chemistry and magnetism are explained by DFT studies.