Hydrazone-based cobalt complexes toward multielectron redox and spin crossover

Abstract

Hydrazone-based derivatives modified by substitution at different positions were utilized to prepare a series of bis-homoleptic cobalt complexes toward multielectron redox and spin crossover.

Crystal structure of bis-[N-(1-pyrazin-2-yl-ethylidene)-cyanoacetic acid-hydrazonato-κ3 O,N,N′)]-zinc(II), C18H16N10O2Zn

“…In the title crystal structure, the central Zn(II) ion is sixcoordinated to two anionic hydrazone ligands by a pair of ON 2 donor sets, thus giving a distorted octahedral coordination geometry. The C-O bond of the hydrazone ligand is in the enolate form, which is supported by the distance of C-O bond being 1.264(5)/1.263(5) Å for C16-O2 and C7-O1, respectively, similar to what was found in other hydrazone ligands [6,7]. The structure is similar to that of the Zn(II) complex with the 2-aceto-pyrazine benzoylhydrazone ligand [6].…”

“…Hydrazones derived from 2-aceto-pyrazine and their metal complexes have been widely investigated mainly due to their excellent biological activities [4][5][6]. However, most research has focused on aryl-hydrazones and investigations on alkylhydrazones are relatively few [4][5][6][7]. Herein, the title complex was synthesized and characterized by X-ray diffraction in this work.…”

Crystal structure of bis-[N-(3-ethyl-1-pyrazin-2-yl-ethylidene)-3-bromo-benzoic acid-hydrazonato-κ3 O,N,N′)]-cadmium(II), C30H28N8O2Br2Cd

“…In the title structure, C=O bonds of the hydrazone ligands are enolized, which could be confirmed by the bond lengths of C-O being 1.254(6) and 1.258(6) Å, respectively. The results are in good agreement with previously known acylhydrazone complexes in the literature [4][5][6][7]. The central Cd(II) ion is surrounded by two independent anionic ligands with N 2 O donor set, thus possessing a distorted octahedral coordination geometry.…”

“…As one type of Schiff bases, hydrazones are important an class of ligands with interesting ligation properties due to the presence of several coordination sites, and are widely applied in the field of insecticides, medicines and analytical reagents [3]. In particular, pyrazine-containing hydrazones and their metal complexes have been widely investigated mainly due to their excellent biological activities [4][5][6][7]. As part of our continuing work, the title complex was synthesized and characterized by X-ray diffraction.…”

Crystal structure of bis(3-chloro-N-(1-(pyrazin-2-yl)ethylidene)benzohydrazonato-k3 N,N′,O)nickel(II), C26H20N8O2Cl2Ni

“…Hydrazones are a class of ligands with interesting ligation properties, and are widely applied for example as analytical reagents [4]. In particular, pyrazine-contained hydrazone and their metal complexes have been widely investigated mainly due to their excellent biological activities [5][6][7][8].…”