Di-μ₂-acetato-diacetato-bis{μ₂-3,3′,5,5′-tetramethoxy-2,2-[ethane-1,2-diylbis(nitrilomethylidyne)]diphenolato}tricobalt(II,III) dichloromethane disolvate

Abstract

The trinuclear title compound, [Co3(CH3COO)4(C20H22N2O6)2]·2CH2Cl2, contains mixed-valence cobalt ions in the following order CoIII–CoII–CoIII where all the three cobalt ions are hexa­coordinated. The central cobalt ion is situated on an inversion centre and is in an all-oxygen environment, coordinated by four phenolate O atoms and two O atoms from bridging acetate groups, while the terminal cobalt ion is hexa­coordinated by two phenolate O atoms, two acetate O atoms and two imine N atoms. This complex contains a high-spin central CoII and two terminal low-spin CoIII i.e. CoIII(S = 0)–CoII(S = 3/2)-CoIII(S = 0). There are weak inter­molecular C—H⋯O inter­actions involving the meth­oxy groups, as well as inter­molecular C—H⋯O inter­actions involving the acetate anions. In addition, the dichoromethane solvate mol­ecules are held in place by weak C—H⋯Cl inter­actions.

Fabrication of Schottky barrier diodes utilizing carboxylate bridged trinuclear mixed valence cobalt(iii/ii/iii) complexes of tetradentate N2O2donor reduced Schiff base ligands

“…The Co(2)⋯Co(1) distances are not sufficiently short enough {3.061(1) Å} to imply any cobalt–cobalt bonding. 47,74–80 The bridging angles, ∠Co(1)–O(1)–Co(2) = 99.95(8)° and ∠Co(1)–O(2)–Co(2) = 99.26(8)° indicate that the cobalt( iii )–O–cobalt( ii ) fragments are non-collinear. 47,75–79 Cobalt( ii )–O distances vary from 2.065(2) to 2.102(2) Å (Table 2), values equivalent to those observed in other high-spin cobalt( ii ) complexes.…”

“…47,74–80 The bridging angles, ∠Co(1)–O(1)–Co(2) = 99.95(8)° and ∠Co(1)–O(2)–Co(2) = 99.26(8)° indicate that the cobalt( iii )–O–cobalt( ii ) fragments are non-collinear. 47,75–79 Cobalt( ii )–O distances vary from 2.065(2) to 2.102(2) Å (Table 2), values equivalent to those observed in other high-spin cobalt( ii ) complexes. 47,75–82 The cobalt( iii )–oxygen and cobalt( iii )–nitrogen distances (Table 2) are within the range 1.897(2)–1.943(2) and 1.977(2)–1.988(2) Å, respectively, which are typical for low-spin cobalt( iii ).…”

2-Bromo-4-chloro-6-(cyclohexyliminomethyl)phenol

“…For the coordination chemistry of Schiff base compounds, see: Xu et al (2011); Suleiman Gwaram et al (2011); Assey et al (2011). For standard bond lengths, see: Allen et al (1987).…”

“…Schiff bases are versatile ligands in coordination chemistry (Xu et al, 2011;Suleiman Gwaram et al, 2011;Assey et al, 2011). As a contribution to a structural study on Schiff base compounds, we present here the crystal structure of the title compound, that was obtained as the product of the reaction of 3-bromo-5-chlorosalicylaldehyde with cyclohexylamine in methanol.…”

Magnetic Properties of End-to-End Azide-Bridged Tetranuclear Mixed-Valence Cobalt(III)/Cobalt(II) Complexes with Reduced Schiff Base Blocking Ligands and DFT Study

“…Schiff bases have been widely used by various groups to prepare many mixed-valence cobalt­(III)/cobalt­(II) complexes, − including a few trinuclear examples. − Macrocyclic Schiff bases prepared by condensation of different diamines with 4-alkyl-2,6-diformylphenols have also been used to prepare dinuclear cobalt mixed-valence complexes − although their magnetic properties have not been reported. On the other hand, many hydroxide-rich Schiff bases have also been used to form dinuclear mixed-valence complexes, including a few examples showing single-molecule magnet (SMM) behavior. − …”