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Structural Trends in Divalent Benzil Bis(thiosemicarbazone) Complexes
Author(s) -
Calatayud David G.,
LópezTorres Elena,
Mendiola M. Antonia,
Pastor César J.,
Procopio Jesús R.
Publication year - 2005
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.200500363
Subject(s) - chemistry , benzil , ligand (biochemistry) , ionic radius , semicarbazone , deprotonation , divalent , non innocent ligand , crystallography , coordination sphere , metal , copper , redox , ionic bonding , chelation , bond length , stereochemistry , inorganic chemistry , ion , crystal structure , organic chemistry , biochemistry , receptor , catalysis
Redox‐related changes in the biological properties of copper bis(thiosemicarbazones) are induced by the backbone of the ligand. To get information about how these changes depend on the structural parameters, three X‐ray structures of complexes with different behaviour of the benzil bis(thiosemicarbazone) ligand have been determined. These include two almost planar copper( II ) complexes with different grades of deprotonation in the ligand and a Zn II complex in which the ligand acts as a monoanion and a nitrate group is bonded to the metal ion in a square‐based pyramid. The changes in the backbone bond lengths agree with the variation in the ionic radius and with the grade of electronic charge delocalisation in the chelate rings; these have consequences for the coordination sphere, allowing the metal to fit slightly better into the ligand cavity, which in turn may affect the complex stability and the redox potential. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)