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Formation and Reactivity of Copper Acetylacetone Bis(Thiosemicarbazone) Complexes
Author(s) -
Bilyj Jessica K.,
Harmer Jeffery R.,
Bernhardt Paul V.
Publication year - 2018
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201801002
Subject(s) - chemistry , acetylacetone , semicarbazone , ketone , pyrazoline , ligand (biochemistry) , reactivity (psychology) , copper , electron paramagnetic resonance , photochemistry , polymer chemistry , medicinal chemistry , inorganic chemistry , organic chemistry , medicine , alternative medicine , pathology , biochemistry , physics , receptor , nuclear magnetic resonance
The complexation reaction mechanism of acetylacetone bis‐thiosemicarbazone ligands (H 2 acacR) with Cu II is explored using a variety of physical methods. The complexes form via a complicated multistep mechanism that is initiated by ring opening of the pyrazoline form of the ligand and leads, ultimately in air, to an oxidised ketone form of the ligand. Tetradentate N 2 S 2 coordinated forms of the intermediate [Cu(acacR)] are stable only under anaerobic conditions. Upon exposure to air these complexes are cleanly oxidised to the ketone complex [Cu(acacRO)] as shown by X‐ray crystallography, electrochemistry, UV/Vis and EPR spectroscopy. The behavior of these complexes contrasts with those of closely related bis‐dithiocarbazate Schiff bases which stabilise Cu III .