625385-03-7Relevant academic research and scientific papers
EPR study of o-semiquinone-catecholate cobalt complexes with bis(diphenylphosphanyl)ethane
Bubnov, Michael P.,Teplova, Irina A.,Cherkasov, Vladimir K.,Abakumov, Gleb A.
, p. 2519 - 2523 (2003)
Three novel cobalt compounds with bis(diphenylphosphanyl)ethane (dppe) and semiquinone and catecholate ligands were synthesized and investigated by EPR spectroscopy (1), in solution. They are: [(dppe)Co(3,6-DBSQ)(CatoxCl)] (1), [(dppe)Co(3,6-DBCat)(phen-SQ)] (2), and [(dppe)Co(3,6-DBSQ)2] (3), where 3,6-DBSQ and 3,6-DBCat are the radical anion and dianion of 3,6-di-tert-butyl-o-benzoquinone, respectively, CatoxCl is the dianion of perchloroxanthrenequinone-2,3, and phen-SQ is the radical anion of phenanthrenequinone. According to the ratio of the redox potentials of the o-quinone fragments, 1 and 2 are mixed semiquinone-catecholate complexes, and the 3,6-di-tert-butyl-o-quinone fragment appears as a semiquinone in 1 and as a catecholate in 2. Compound 3 exists as a mixture of redox isomers, namely semiquinone-catecholate and bis-semiquinone species. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
Catecholato complexes of cobalt and nickel with 1,4-disubstituted-1,4-diazabutadiens-1,3 and 1,2-bis(diphenylphosphino)ethane
Bubnov, Michael P.,Teplova, Irina A.,Druzhkov, Nikolay O.,Fukin, Georgy K.,Cherkasova, Anna V.,Cherkasov, Vladimir K.
, p. 527 - 535 (2015/05/20)
Divalent cobalt and nickel form four-coordinate complexes with sterically hindered 3,6-di-tert-butylcatecholato dianion (3,6-DBCat) and neutral bidentate 1,4-disubstituted-1,4-diazabutadiens-1,3 (DAB). Structural study of (1,4-di-tert-butyl-1,4-diazabutadiene-1,3)(3,6-di-tert-butyl-catecolato)nickel and (1,4-bis-(2,6-di-iso-propylphenyl)-2,3-dimethyl-1,4-diazabutadiene-1,3)(3,6-di-tert-butyl-catecolato)cobalt indicates square-planar environment of metals. Chemical one-electron oxidation of nickel complexes proceeds through catecholate ligand and leads to o-semiquinonato adducts. EPR spectral parameters indicate preservation of square-planar configuration after oxidation. Complexes (DAB)M(Cat) (M = Ni, Co) undergo neutral ligand substitution reactions. [Figure not available: see fulltext.]
