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Mono‐ and Dinuclear Heteroleptic Cobalt Complexes with α‐Diimine and Polyarene Ligands
Author(s) -
Wang Xuting,
Zhao Yanxia,
Gong Shida,
Liu Bin,
Li QianShu,
Su JiHu,
Wu Biao,
Yang XiaoJuan
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201500983
Subject(s) - diimine , pyrene , cobalt , chemistry , ligand (biochemistry) , electron paramagnetic resonance , photochemistry , metal , anthracene , crystallography , redox , medicinal chemistry , stereochemistry , inorganic chemistry , organic chemistry , biochemistry , physics , receptor , nuclear magnetic resonance , catalysis
Reactions of the dimeric cobalt complex [(L − Co) 2 ] ( 1 , L=[(2,6‐ i Pr 2 C 6 H 3 )NC(Me)] 2 ) with polyarenes afforded a series of mononuclear and dinuclear complexes: [LCo(η 4 ‐anthracene)] ( 2 ), [LCo(μ‐η 4 :η 4 ‐naphthalene)CoL] ( 3 ), and [LCo(μ‐η 4 :η 4 ‐phenanthrene)CoL] ( 4 ). The pyrene complexes [{Na 2 (Et 2 O) 2 }{LCo(μ‐η 3 :η 3 ‐pyrene)CoL}] ( 5 ) and [{Na 2 (Et 2 O) 3 }{LCo(η 3 ‐pyrene)}] ( 6 ) were obtained by treating precursor 1 with pyrene followed by reduction with Na metal. These complexes contain three potential redox active centers: the cobalt metal and both α‐diimine and polyarene ligands. Through a combination of X‐ray crystallography, EPR spectroscopy, magnetic susceptibility measurement, and DFT computations, the electronic configurations of these complexes were studied. It was determined that complexes 2 – 4 have a high‐spin Co I center coupled with a radical α‐diimine ligand and a neutral polyarene ligand. Whereas, the ligand L in complexes 5 and 6 has been further reduced to the dianion, the cobalt remains in a formal (I) oxidation state, and the pyrene molecule is either neutral or monoanionic.