3,5-disusbtituted-N-hydroxyalkylpyrazole Cu(II) compounds: Anion effect on dimensionality, supramolecular structure and magnetic properties

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

“…1). Contrary to most of the reported dimers with other Nhydrox-yethylpyrazoles [22,23,[42][43][44][45] 1). The second one, [CuO2N2] (τ4 = 0.26) [46], is coordinated exclusively to the pyrazole ligand, sharing the bidentate oxygens of the first core (Cu-O bond lengths at 1.8958(16) and 1.9062(17) Å, Table 1) and completing their coordination with the nitrogen atoms (Cu-N bond lengths at 1.945(2) and 1.961(1) Å, Table 1).…”

“…Moreover, when considering our previously published results of the reactivity of the similar 3,5-disusbstituted ligand 2-(3,5-dimethyl-1Hpyrazol-1-yl)ethanol against Cu(NO3)2⋅3H2O [23], where the ligand remained intact, this behaviour is even more striking. This suggests that electronic effects caused by the substituents in positions 3-and 5-to the pyrazole ring may result in the NPz-C bond being more susceptible to cleavage promoted by the Cu(NO3)2⋅3H2O.…”

“…For instance, pyrazole ligands bearing groups such as amines [16,17], thioethers [18], sulfoxides/sulfones [19], phosphines [20], phosphinites [21] and alcohols [22] have been obtained, and their coordination behaviour against different metal salts studied. In this sense, we have recently reported the coordination behaviour of one N,O-hybrid pyrazole ligand (2-(3,5-dimethyl-1H-pyrazol-1-yl) ethanol against different Cu(II) salts [23]. The morphology of the resulting complexes shows a direct dependence on the protonation of the alcohol moiety, which results in the formation of dimers or polymers when deprotonated or in the formation of monomers or ionic complexes when protonated.…”

“…In recent reports, it has been seen that the inclusion of ligands appended with hydrogen or π donor groups could promote second coordination sphere interactions leading to significant changes in the supramolecular structure and host-guest recognition interactions of the resulting coordination complexes [24][25][26]. Thus, by incorporating aromatic substituents in the pyrazole framework, the second coordination sphere interactions may promote molecular and supramolecular architectures differing significantly of those obtained with 2-(3,5-dimethyl-1H-pyrazol-1-yl)ethanol [23].…”

Tuning the architectures and luminescence properties of Cu(i) compounds of phenyl and carboranyl pyrazoles: the impact of 2D versus 3D aromatic moieties in the ligand backbone

“…45 There are however some more reports on neutral polypyrazolyl ligands, leading to a wide variety of coordination polymers. [46][47][48][49] As part of our on-going research on pyrazole [50][51][52][53][54][55] and carborane [56][57][58][59][60][61][62][63] based ligands for functional metal compounds, we were interested in exploring the impact of adding the icosahedral carborane clusters to the pyrazole fragment on the coordination to Cu(I) ions and the corresponding luminescence properties. Icosahedral carboranes 1,n-C 2 B 10 H 12 (n = 2, 7 or 12) are a class of commercially available and exceptionally stable 3D-aromatic boron-rich clusters that possess materialfavourable properties such as thermal and chemical stability and high hydrophobicity.…”