@article{https://doi.org/10.1002/ejic.202100142,
author = {Mohammadnezhad, Gholamhossein and Ahfad, Neda and Meghdadi, Soraia and Farrokhpour, Hossein and Schmitz, Simon and Haseloer, Alexander and Buchholz, Axel and Plass, Winfried and Klein, Axel},
title = {Dinuclear Nickel(II) and Copper(II) Complexes of 8-Quinoline-1H-pyrazole-3-carboxamide: Crystal Structure, Magnetic Properties, and DFT Calculations},
journal = {European Journal of Inorganic Chemistry},
volume = {n/a},
number = {n/a},
pages = {},
keywords = {Copper, Density functional calculations, Magnetic properties, Nickel, Structure elucidation},
doi = {https://doi.org/10.1002/ejic.202100142},
url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/ejic.202100142},
eprint = {https://chemistry-europe.onlinelibrary.wiley.com/doi/pdf/10.1002/ejic.202100142},
abstract = {Abstract Homoleptic dinuclear complexes [M2(qpyzc)2] (M=Cu (1) or Ni (2) were obtained from the readily synthesised trischelate pyrazole-based qpyzc ligand (H2qpyzc=8-quinoline-1H-pyrazole-3-carboxamide). Their crystal and molecular structures, magnetic properties, and UV-vis spectra were reported alongside with DFT and TD-DFT calculations. Trigonality index τ’4 values of 0.25 and 0.21 for the Cu and Ni centres, respectively reveal a marked distortion from square planar geometry. The two metal coordination planes within a complex are tilted towards each other with 40.2(1)° for Cu(II) and 34.5(2)° for Ni(II). The central six-membered M2N4 metallocycle is almost planar and the two anionic pyrazolate rings are tilted towards each other by 37.4(1)° (1) and 38.5(2)° (2), respectively. Regardless of this peculiar bonding situation magnetic measurements on 1 are in line with medium-sized antiferromagnetic coupling with a coupling constant of J=−100 cm−1, an isotropic g value of 2.11 and an S=0 ground state. Complex 2 seems to be diamagnetic. DFT calculations gave an excellent agreement between calculated and experimental metrics of the complexes and supported the prevalence of the singlet ground state for 1. TD-DFT calculated UV-vis absorption spectra agree well with observed absorptions and the red colour of both compounds.}
}