Synthesis, structures, and spectral properties of biomimetic azomethine metal chelates with chromophores CuN2S2, CuN2O2, and CuN2Se2. Crystal structure of bis[4-(benzyl)aldimino-3-methyl-1-phenyl-5-pyrazolothiolato]copper(II)

Copper(ii) chelates of composition CuL2 were synthesized based on 4-aminome thylene derivatives of 5-thiopyrazoles (LH). The complexes were studied by UV, IK, ESR, and EXAFS spectroscopy, magnetochemistry, and X-ray diffractio n analysis. The coordination polyhedra in the complexes are pseudotetrahedr a or octahedra of the types CuN2S2 or CuN4S2, respectively, which are disto rted due to the Jahn-Teller effect. The UV and ESR spectra of copper chelat es with a six-coordinate metallocycle formed by the N and S atoms of the az omethine ligand and the nitrogen atom of the quinoline substituent (R) of t he C=N-R fragment are most similar to the spectra observed for metals invol ved in the active centers of natural metalloenzymes ("blue" copper proteins ).