Cu(II) and Zn(II) Complexes with Dinitrobenzoates and Pyrazolyl Ligands: Structural and Thermal Stability Influence of N–H Moiety

Abstract

The synthesis and characterization of air-stable Cu(II) and Zn(II) complexes with 3,5-dinitrobenzoate (DNB) and 3,5dimethylpyrazole (L1) or bis(3,5-dimethylpyrazol-1-yl)methane (L2) are described. Three of these complexes exhibit a monomeric structure, while the Cu(II) complex with L2 is a trinuclear complex. Density functional theory calculations were performed to understand the unexpected formation of the three-centered compound. In agreement with the X-ray crystal structure, the N−H moiety present in L1 was identified as possible driving force to obtain monomeric structures, while L2, without it, can favor the trinuclear complex formation. Thermal studies were carried for the complexes, and it was observed that the presence of the azole ligand allows the decomposition of the complexes at lower temperatures due to the presence of acidic protons, being especially important for L1.

Synthesis of Two Mononuclear Schiff Base Metal (M = Fe, Cu) Complexes: MOF Structure, Dye Degradation, H2O2 Sensing, and DNA Binding Property

“…1−14 In general, the Schiff base can assemble the metal ions to develop metal–organic framework (MOF) compounds and shows different properties like dye adsorption, sensing, semiconductor, and biological properties. 15−23…”

“…The Schiff base metal complexes are used extensively in the field of materials science, including catalyst, supramolecular chemistry, anticancer, antimicrobial, antioxidants, electrochemistry, photocatalysts, DNA binding, and energy materials. − In general, the Schiff base can assemble the metal ions to develop metal–organic framework (MOF) compounds and shows different properties like dye adsorption, sensing, semiconductor, and biological properties. − …”

Influence of the Lewis basicity hardness of crystallization solvents on the coordination sphere of the complex [Co(3,5-dinitrobenzoate-O,O′)2]: crystallographic and theoretical analysis

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] However, benzoates not only influence the dimensionality of the network in terms of polymeric structures but also facilitate the formation of polynuclear coordination complexes due to their behaviour as bridging bidentate ligands. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] The interest for the structural variation in these complexes with DNB, and in general benzoate ligands, lies in their potential applications in catalysis and magnetism, and as compounds with biological activity. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] The interest for the structural variation in these complexes with DNB, and in general benzoate ligands, lies in their potential applications in catalysis and magnetism, and as compounds with biological activity. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] In particular, we have previously published the synthesis and characterization of seven CoIJII) complexes of pyrazole derivatives and dinitrobenzoate ligands. 14 Interestingly, in our attempts to obtain crystals of suitable quality by varying the solvent of crystallization, different crystal structures and mono/trinuclear molecules were found as observed previously.…”

Crystal structure and Hirshfeld surface analysis of the orthorhombic polymorph of a ZnII complex with 3,5-dinitrobenzoic acid and ethylenediamine

“…Among them, 29 hits are zinc complexes, of which 14 have the coordination number four. In all of these complexes, two DNBA anions are coordinated in a monodentate fashion and only in structures JOHYEN(Torres et al, 2019) and VIQFAE(Dey et al, 2013) is the coordination of Zn II accomplished by chelating ligands: 1,1 0 -methylenebis(3,5-dimethyl-1H-pyrazole and 2,2 0 -bipyridyl for JOHYEN and VIQFAE, respectively.…”