The magnetic exchange interaction via N–H⋯O-bonding in copper(II) complex with 1-phenyl-3-methyl-4-formylpyrazol-5-one 2-quinolylhydrazone

• Published in: Inorganica Chimica Acta 2013-08, Vol.405, p.169-175
• Main Authors: Levchenkov, Sergey I., Shcherbakov, Igor N., Popov, Leonid D., Lukov, Vladimir V., Minin, Vadim V., Starikova, Zoya A., Ivannikova, Elena V., Tsaturyan, Arshak A., Kogan, Victor A.
• Format: Article
• Language: English
• Subjects: Copper complexes; DFT calculations; Exchange interaction; X-ray crystal structure
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2013.05.032

Intermolecular exchange coupling (2J=−3.25cm−1) between copper(II) centers through unusually long superexchange pathway Cu–N–N⋯H–O–C–O–Cu is studied experimentally (XRD, ESR and magnetic susceptibility measurements) and DFT modeling. •Antiferromagnetic exchange coupling between Cu(II) centers is found in crystals of mononuclear Cu(II) complex.•Intermolecular exchange coupling between Cu(II) centers is attributed to NH⋯O hydrogen bonding.•DFT–BS modeling of exchange interaction is used to support the proposed superexchange pathway. The mononuclear copper(II) complex [CuL(CH3COO)], where L is monoanion of 1-phenyl-3-methyl-4-formylpyrazol-5-one 2-quinolylhydrazone has been synthesized. The weak intermolecular antiferromagnetic exchange interaction between copper(II) ions has been determined with the data of ESR spectroscopy and cryomagnetic measurements (2J=−3.25cm−1). XRD data in combination with DFT calculations of exchange parameter within broken symmetry approach indicates that intermolecular exchange coupling is going through NH⋯O hydrogen bonds in centrosymmetric H-bonded dimers.