The Cu(II) complexes with bis(pyrazole-1-yl)methane and its derivatives: Synthesis, crystal structure, and magnetic properties

Water Dissociation of a Dinuclear Bis(3,5‐dimethylpyrazolyl)methane Copper(II) Complex: X‐ray Diffraction Structure, Magnetic Properties, and Characteristic Absorption of the (CuN2Cl2)2 Core

“…This situation contrasts with that found for the aforementioned di(µ‐chloro)dicopper(II) analogue, obtained with the bromo‐substituted ligand derivative, which shows moderately strong antiferromagnetic coupling between the two Cu II ions ( J = –66.7 cm –1 ), despite the fact that both compounds possess similarly short Cu–Cl bond lengths and bent Cu–Cl–Cu bond angles. The weakening of the antiferromagnetic coupling in 1 can then be explained by the larger trigonal‐bipyramidal distortion of the metal centers and the greater deviations from the planar molecular conformation, as discussed above.…”

“…The relatively large trigonal‐bipyramidal distortion of the metal centers in 1 leads to an overall bifolded molecular conformation, as reflected by the value of 39.1° for the dihedral bifold angle ( σ ) between the central Cu(1)Cl(2)Cu(1′)Cl(2′) plane and the peripheral Cu(1)Cl(2)Cl(3)N(13) plane. This situation contrasts with that previously reported for the related dichloro‐bridged dicopper(II) complex of the formula [{CuCl( L )} 2 (µ‐Cl) 2 ] [ L = bis(4‐bromo‐3,5‐dimethylpyrazol‐1‐yl)methane], which shows a smaller trigonal‐bipyramidal distortion of the five‐coordinate metal centers, and hence, a lower deviation from the planar molecular conformation ( τ = 0.24 and σ = 20.8°) . Within the Cu 2 Cl 2 bridging core of 1 , the values of the Cu–Cl bond lengths ( R = 2.32–2.37 Å) and Cu–Cl–Cu interbond angle ( θ = 97.1°) are, however, similar to those of the di(µ‐chloro)dicopper(II) analogue with the bromo‐substituted ligand derivative ( R = 2.32–2.36 Å and θ = 97.7°) .…”

“…We have been able to characterize the yellow complex as a dinuclear Cu II compound with the formula [{CuCl( L )} 2 (µ‐Cl) 2 ] ( 1 ), showing a similar structure to that reported for the dimeric copper complex based on the brominated derivative of L and to that reported for L with other metal chlorides , . Herein, we describe the structural characterization of complex 1 and its dissociation in the presence of water to produce [CuCl{H 2 C(3,5‐Me 2 pz) 2 } 2 ]Cl · 3H 2 O, as well as the magnetic properties and theoretical studies of 1 .…”

“…The first structure corresponds to complex 1 ; the second is a similar compound, in which the nitrogenous ligand is substituted at the 4‐position of the pyrazoles with bromide. The distances between the metal with the ligand and the chlorine atoms Cl1 and Cl1′ are similar for these two complexes . However, a significant difference is found in the bond length with Cl2, which shows considerable shortening.…”

X-ray crystallographic insights into post-synthetic metalation products in a metal–organic framework

“…However, we note that a similar Cu 2+ coordination environment was reported by Lider et al [25] from the reaction of bis(4-iodo-3,5-dimethyl-pyrazolyl)methane (bidmp) with copper(II) nitrate. Although the relative position of the solvent and nitrate anions differs between the two materials, this and other similar discrete metal complex structures [26][27][28] confirm the MOF-bound copper complex to be in a coordination environment typical for Cu(II). As described above, the pore surrounding the coordinating site in MOF 1 allows movement of non-coordinated nitrate anions, which is reminiscent of the solution state.…”