1379685-00-3Relevant academic research and scientific papers
Binuclear arylnickel complexes with bridging bis(arylimino)-1,4-pyrazine ligands
Klein, Axel,Biewer, Christian,Hamacher, Claudia,Hurkes, Natascha,Perez Outeiral, Jessica,Paniagua, Erik Mora,Schmieder, Ann-Kathrin,Schueren, Andreas O.,Burma, Prabhakara Rao,Ciszewski, James T.,Vicic, David A.
, p. 2444 - 2455 (2012)
Binuclear organometallic nickel complexes of the type [(μ-NN){Ni(Mes)Br} 2] {NN = α-diimine chelate ligand of the type 2,5-bis[1-(aryl)iminoethyl]pyrazine; Mes = mesityl = 2,4,6-trimethylphenyl} have been prepared and characterised electrochemically and spectroscopically in detail. A combination of NMR spectroscopy and quantum chemical calculations allowed the assignment of stereoisomers and their relative stability. The long-wavelength absorptions (600-1000 nm) assignable to charge-transfer transitions reveal a marked electronic coupling of the two metal centres over the ligand bridge via their low-lying π* orbitals. The reversible reductive electrochemistry yields stable radical anionic complexes with mainly ligand-centred spin density as shown by electron paramagnetic resonance (EPR) spectroscopy and UV/Vis spectroelectrochemistry of the free ligands and their nickel complexes in combination with DFT calculations. Preliminary investigations of the complexes as catalysts in Negishi cross-coupling reactions gave promising results. Copyright
