Azine‐Bridged Octanuclear Copper(II) Complexes Assembled with a One‐Stranded Ditopic Thiocarbohydrazone Ligand

Abstract

Multinuclear metal complexes are of interest in different fields of research. They are found in biological systems such as ferritin, [1,2] those with high-spin ground states can act as superparamagnets [3,4] and molecular nanomagnets, [5, 6] and[*] Prof. V. B. Arion

Dinuclear Copper(II) Complexes with Bis‐thiocarbohydrazone Ligands

“…Other azine-bridged dicopper systems with roughly parallel copper coordination planes also exhibit moderate to large antiferromagnetic coupling. [10][11]22,23] Indeed, Thompson et al [24] have elucidated the way in which the coupling crosses over (i.e., -2J = 0) at an interplane twist angle of about 85°. The coupling is antiferromagnetic at lower twist angles, -2J approaching 225 cm -1 when the coordination planes are parallel (interplane angle 0°).…”

“…[9,10] Recently, two azinebridged octanuclear copper(II) complexes, assembled from bis(2-hydroxybenzaldehyde) thiocarbohydrazone were re-ported. [11] In these 24-membered metallomacrocycles, the ligand used its maximal donor capacity in a manner unprecedented for thiocarbohydrazone coordination chemistry. Continuing our work [11] on the coordination chemistry of bis(salicylaldehyde) thiocarbohydrazones, we have now prepared new copper(II) complexes, in order to establish the influence of the phenyl ring substituents on their nuclearity, geometry and magnetic properties.…”

“…[11] In these 24-membered metallomacrocycles, the ligand used its maximal donor capacity in a manner unprecedented for thiocarbohydrazone coordination chemistry. Continuing our work [11] on the coordination chemistry of bis(salicylaldehyde) thiocarbohydrazones, we have now prepared new copper(II) complexes, in order to establish the influence of the phenyl ring substituents on their nuclearity, geometry and magnetic properties. The substituents were placed at strategic positions with respect to the donor sets, Scheme 1. modifying the electronic environment around the metal centers (Scheme 1).…”

“…In addition, we eschewed the use of added base, reasoning that the degree of self-association of the dicopper units may become limited by retention of protons on groups that act as bridging donors in the octanuclear systems. [11] The crystal and molecular structures of these complexes [Cu 2 (HL Me,Et )(HSO 4 )(MeOH) 2 ]·MeOH have been determined by single-crystal X-ray diffraction.…”

Synthesis and Crystal Structure of a Heptanuclear and an Octanuclear Copper(II) Complex Derived from α‐D‐Glucofuranoses

“…Octanuclear metallamacrocyclic complexes have been synthesised from the pentadentate trianionic Schiff base ligand N,NЈ-(2-hydroxypropane-1,3-diyl)bis(salicylaldimine) [10] or ditopic thiocarbohydrazones. [11] Efficient cleavage of supercoiled DNA in the presence of H 2 O 2 was observed for an octanuclear copper(II) complex. [12] Derived from cytidine, [13] dithiocarbamates, [14] bis(diphenylphosphanyl)amide and (Me 3 Si) 2 Se [15] and methylsiloxane [16] different supramolecular arrangements of Cu 8 clusters have been be obtained.…”