Determination of structures of Cu(II) and Ni(II) complexes based on 4-methyl-2,6-bis{[2-(4,6-dimethylpyrimidin-2-yl)-hydrazono]methyl}phenol by combine experimental and theoretical approaches

Synthesis, structure and biological properties of a series of dicopper(bis-thiosemicarbazone) complexes

“…According to literature data, complex compounds based on 2,6-diformyl-4- R -phenol are known to have methoxy, ethoxy or hydroxy bridging molecules between Cu( ii ) atoms. 36,48–51 In these cases, the authors report Cu–O distances between 1.8 and 1.9 Å that are characteristic for Cu-methoxo or ethoxo ligands, while these distances increase up to 2.5–2.6 Å for Cu–OH 2 , Cu–OHMe or Cu–OHEt bonds. For complex 4′ , [Cu 2 (H 2 L 1 )(OH)](ClO 4 ) 2 , the external bridge between the two Cu( ii ) atoms is identified as a hydroxo ligand ( d Cu–O = 1.907–1.911 Å), while it was an ethoxo ligand in the complex 4 synthesized in powder form.…”