@article{https://doi.org/10.1002/ejic.202001129,
author = {Mohammadnezhad, Gholamhossein and Amirian, Ali Mohammad and Görls, Helmar and Plass, Winfried and Sandleben, Aaron and Schäfer, Sascha and Klein, Axel},
title = {Redox Instability of Copper(II) Complexes of a Triazine-Based PNP Pincer},
journal = {European Journal of Inorganic Chemistry},
volume = {2021},
number = {12},
pages = {1140-1151},
keywords = {Copper, PNP pincer ligands, Redox chemistry, Spectroelectrochemistry, Azide click reaction},
doi = {https://doi.org/10.1002/ejic.202001129},
url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/ejic.202001129},
eprint = {https://chemistry-europe.onlinelibrary.wiley.com/doi/pdf/10.1002/ejic.202001129},
abstract = {Abstract The new Cu(I) complex [Cu(PNPNTPh-Ph)Cl] (1) containing the tridentate PNP pincer ligand N,N′-bis(diphenylphosphino)-2,6-diamino-4-phenyl-1,3,5-triazine was obtained from the reaction of [Cu(SMe2)Cl]n with the ligand as ether solvate 1.0.5Et2O. 1 was independently obtained from a reaction mixture containing the ligand and the Cu(II) precursor CuCl2.2H2O in 50 \% yield alongside with the Cu(II) coordination polymer [Cu(O2PPh2)2]n (2). From the reaction of Cu(NO3)2 ⋅ 3H2O with PNPNTPh-Ph in the presence of pyridine the complexes [Cu(O2PPh2)2(Py)2(H2O)] (3), [Cu(O2PPh2)(Py)2(NO3)]2 (4), and [Cu(Py)4(NO3)2].Py (5), were obtained, 2, 3, and 4 contain diphenyl-phosphinate ligands. The underlying redox reaction of the ligand and Cu(II) yielding the oxidised ligands observed in the by-products and the Cu(I) product complex was further studied using electrochemistry and UV-vis spectroelectrochemistry. Attempts to synthesise the Cu(II) complex [Cu(PNPNTPh-Ph)(NO3)2] (6) in a mechanochemical experiment gave evidence for this unprecedented species from ESI-MS(+) and EPR spectroscopy but also revealed its very high sensitivity to air and moisture. The catalytic activity of 1 was investigated in the azide-alkyne cycloaddition yielding various 1-benzyl-4-phenyl-1H-1,2,3-triazoles. The environmentally benign (“green”) and cheap EtOH/H2O solvent mixture turned out to be very suitable. Melting points, FT-IR, and NMR spectra of the triazole products were analysed.},
year = {2021}
}