Copper complexes from 3,5-disubstituted N-hydroxyethylpyrazole ligands: Cleavage of C N bond as well as formation of second coordination sphere complexes

Effects on the magnetic interaction caused by molecular recognition in complexes of 1,2-azole-based oxamate and [Cu(bpca)]+ units

“…Focusing on 1 H -pyrazole-based ligands, their coordination chemistry is very rich due to the possibility of coordinating to metal atoms in their neutral or deprotonated form since its NH group can be easily deprotonated in the presence of transition metal ions and a base (apparent p K a = 19,8 for 1 H -pyrazole in DMSO). The pyrazolate anion acts as a bis-monodentate kN:kN′ ligand, forming di-, 22–38 tri-, 22–24,37–47 tetra- 22,48–54 and polymetallic synthons 55–60 or even coordination polymers. 61–64 Relatively strong magnetic interactions between paramagnetic centers such as Cu II , Co II , and Fe II can be mediated through this coordination mode.…”