A remarkable anion effect on the crystal packing of two analogous copper complexes from a thiophene-containing phenol-based ligand

End‐to‐End Thiocyanato‐Bridged Helical Chain Polymer and Dichlorido‐Bridged Copper(II) Complexes with a Hydrazone Ligand: Synthesis, Characterisation by Electron Paramagnetic Resonance and Variable‐Temperature Magnetic Studies, and Inhibitory Effects on Human Colorectal Carcinoma Cells

“…In a non-coordinating solvent (e.g., CH 2 Cl 2 , CHCl 3 , toluene) or in a mixture of non-coordinating solvent (e.g., 50:50 v / v CH 2 Cl 2 /toluene), the structure is retained (see Figure 8 b), as observed for other similar compounds. [39] On the contrary, in a coordinating solvent (e.g., DMSO or DMF), the longest Cu–Cl bond is broken and mononuclear copper(II) species are formed; these observations are in agreement with what is found in many other similar complexes 36c, e,. [40] The EPR spectrum in DMSO shows an axial symmetry and d x 2 − y 2 ground state (Figure 9 a; for the simulated spectrum, see Figure S6 in the Supporting Information).…”

“…[ 39 ] On the contrary, in a coordinating solvent (e.g., DMSO or DMF), the longest Cu–Cl bond is broken and mononuclear copper(II) species are formed; these observations are in agreement with what is found in many other similar complexes. 36c , e , [ 40 ] The EPR spectrum in DMSO shows an axial symmetry and d x 2 − y 2 ground state ( Figure 9 a ; for the simulated spectrum, see Figure S6 in the Supporting Information). The spectral parameters ( g || =2.251, A || =168×10 −4 cm −1 , g ⊥ =2.052, A ⊥ =14×10 −4 cm −1 ), though slightly different from those measured for 1 in DMSO, are consistent with the presence of a chloride rather than a thiocyanato ligand in the fourth equatorial position of the copper ion.…”

Double azido/cyanato bridged copper(II) dimers incorporating tridentate nitrogen donors Schiff base: Structure, EPR and magnetic studies

“…8). This has been observed for other polynuclear copper(II) complexes [53][54][55][56][57][58][59][60][61][62]. The relevant EPR parameters, g z = 2.232, A z = 182.1×10 -4 cm -1 (DMSO), g z = 2.230, A z = 180.1× 10 -4 cm -1 (DMF) and g z = 2.229, A z = 180.7×10 -4 cm -1 (CH 3 CN), indicate the structure formed in these three solvents is very similar.…”

Pyridine-2,6-Dicarboxylic Acid Esters (pydicR2) as O,N,O-Pincer Ligands in CuII Complexes

“…Thus, the observed spectra represent the overall geometry around Cu II than the ligand strength of Cl − , DMF, and O atoms in the O, N, O ligands. The mononuclearcompounds (HNEt 3 )[Cu(pydicMe 2 )Cl 3 ] and (HNEt 3 )[Cu(pydicPh 2 )Cl 3 ] reveal EPR spectra of axial symmetry with g || > g ⊥ in the solid (Figure 8), which is typical for elongated octahedral or square pyramidal Cu II complexes [23,[47][48][49][50][51][52]. The Cu hyperfine structure (coupling to the 63 Cu (69.17%) and 65 Cu (30.83%) nuclei with I = 3/2 [53]) was not observed in line with observations for similar mononuclear complexes [46,52].…”