Search

To improve understanding of copper at the active site of Type 1 copper proteins, CuI and CuII complexes of 1,8-dithia-4,11-diazacyclotetradecane, shown in FIGREFFig. 1/FIGREF, have been successfully isolated and structurally characterized by X-ray crystallography. In these compounds, both CuI and CuII are centered in the plane of the macrocycle containing two sulphur and two nitrogen heteroatoms comprising the distorted tetrahedral/square planar coordination geometry. The UV/VIS spectra, electrochemistry and EPR properties have been obtained for the CuII complex 2. Three absorption bands at 295 nm, 354 nm, and 545 nm are observed in aqueous solution at a pH of 5. These bands have been assigned to the N → CuII and S → CuII charge transfer bands and the d–d transitions respectively. The CuI/II redox midpoint potential of complex 2 in CH3CN is +403 mV versus NHE. [ABSTRACT FROM AUTHOR]