Copper complexes from 3, 5-disubstituted N-hydroxyethylpyrazole ligands: Cleavage of CN bond as well as formation of second coordination sphere complexes. (1st January 2022)

• Record Type: Journal Article
• Authors: Soldevila-Sanmartín, Joan; Calvet, Teresa; Font-Bardia, Mercè; Planas, José G.; Pons, Josefina
• Is Part Of: Polyhedron. Volume 211(2022)
• Publication Date: 2022-01-01
• Subjects: Cu(II) complexes -- N, O-hybrid ligands -- Pyrazole ligands -- Magnetic properties; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2021.115543
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Reactivity of two 3, 5-disubstituted N -hydroxyethylpyrazole ligands against CuCl2 ·2H2 O and Cu(NO3 )2 ·3H2 O yielded four compounds, showing remarkable structural diversity. An unexpected ligand cleavage along the NPZ -Cu bond was observed upon reaction with Cu(NO3 )2 ·3H2 O, a behaviour previously unreported for this family of ligands. Abstract: The coordination behaviour of two N, O -hybrid hydroxyethylpyrazole ligands, 2-(3, 5-diphenyl-1 H -pyrazol-1-yl)ethanol, HL1; and (2-(3, 5-di(2-pyridyl)-1 H -pyrazol-1-yl)ethanol, HL2; with CuCl2 ·2H2 O and Cu(NO3 )2 ·3H2 O were studied. Four copper complexes: [CuCl(µ-L1)]2 ·HL1 (1), [CuCl2 (HL2)]·H2 O (2A), [Cu(NO3 )(3, 5-hdppz)(µ-L1)]2 ·2CH3 CN (3), (3, 5-hdppz = 3, 5-diphenylpyrazole) and [Cu(H2 O)(3, 5-dpypz)]2 (NO3 )2 ·H2 O (4), (3, 5-dpypz = 3, 5-(2-pyridyl)pyrazolate) were isolated and characterized by analytical methods and spectroscopical studies. From their crystal structure, a Npz -C bond cleavage was observed for HL1 and HL2 upon reaction with Cu(NO3 )2 ·3H2 O, yielding the unexpected complexes 3 and 4, respectively. Overall, these complexes provided great structural diversity, as dimers (asymmetric and symmetric), monomers and ionic complexes were obtained. Finally, magnetic susceptibility measurements for 3 were carried out, showing the dependence of the magnetic moment on Cu-O-Cu angles.