An unusual coordination of a 4-azopyrazol-5-one heterocyclic derivative with metals. Synthesis, X-ray studies, spectroscopic characteristics, and theoretical modeling

摘要

Graphical abstract Some derivatives of traditional 4-azopyrazol-5-one organic ligands can undergo an unusual coordination which leads to formation of tetranuclear complexes containing two unequivalent metal cations. A ferromagnetic exchange interaction exists in pairs of differently coordinated metal ions. Spectroscopic characteristics and stability of the complexes are also discussed. Display Omitted Highlights ? A series of novel transition and rare-earth metal complexes of (Z)-4-((1-(benzo[d]thiazol-2-yl)-3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-4-yl)diazenyl)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (HL) were isolated and identified by FT IR, EPR, 1H NMR, and UV–VIS spectroscopy. ? The crystallographic data for [Cu2Cl3(L)(H2O)]2·1.5H2O·CH2Cl2 were obtained. ? The quantum chemical calculations indicate the existence of a ferromagnetic exchange interaction in pairs. ? The complex formation constants in water-ethanol solutions were determined. Abstract A series of novel transition and rare-earth metal complexes of (Z)-4-((1-(benzo[d]thiazol-2-yl)-3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-4-yl)diazenyl)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (HL) were isolated and identified by FT IR, EPR, 1H NMR, and UV–VIS spectroscopy. The crystallographic data for [Cu2Cl3(L)(H2O)]2·1.5H2O·CH2Cl2