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Novel Dinuclear Redox‐isomeric Complexes with a Tetrapodal Pyridine‐based Ligand
Author(s) -
Bubnov Michael P.,
Skorodumova Nina A.,
Zolotukhin Alexey A.,
Arapova Alla V.,
Baranov Evgenii V.,
Stritt Anika,
Ünal Alper,
Grohmann Andreas,
Heinemann Frank W.,
Bogomyakov Artem S.,
Smirnova Natal'a N.,
Cherkasov Vladimir K.,
Abakumov Gleb A.
Publication year - 2014
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201400242
Subject(s) - chemistry , pyridine , cobalt , diamine , benzoquinone , electron paramagnetic resonance , tautomer , ligand (biochemistry) , redox , crystallography , medicinal chemistry , stereochemistry , polymer chemistry , inorganic chemistry , organic chemistry , biochemistry , physics , receptor , nuclear magnetic resonance
Tris‐ o ‐semiquinonato cobalt complexes react with a tetrapodal pyridine‐derived ligand to form dinuclear cobalt compounds of general formula (OMP)[Co Q 2 ] 2 , where OMP = 2,2′‐(pyridine‐2,6‐diyl)bis( N 1 , N 1 , N 3 , N 3 ‐tetramethylpropane‐1,3‐diamine), Q = mono‐ or dianion of 3,6‐di‐ tert ‐butyl‐ o ‐benzoquinone (complex 1 ) and it derivatives: 3,6‐di‐ tert ‐butyl‐4,5‐ N , N ′‐piperazino‐ o ‐benzoquinone (complex 2 ), and 3,6‐di‐ tert ‐butyl‐4‐Cl‐ o ‐benzoquinone (complex 3 ). Single crystal X‐ray crystallography of 1 and 3 indicates two bis‐quinonato cobalt units bound by an OMP ligand, which acts as a bridge. Each central cobalt atom is chelated by one N 1 , N 1 , N 3 , N 3 ‐tetramethylpropane‐1,3‐diamine and two o ‐quinonato fragments. The nitrogen atom of the pyridine ring is uncoordinated. All complexes were characterized by NIR‐IR and EPR spectroscopy, precise adiabatic vacuum calorimetry, and by variable‐temperature magnetic susceptibility measurements. All data indicate a reversible thermally driven redox‐isomeric (valence tautomeric) transformation in the solid state for all complexes.