Cobalt(II) bis(1,4,7-trithiacyclononane): a low-spin octahedral complex

Cobalt Complex with Redox-Active Imino Bipyridyl Ligand for Electrocatalytic Reduction of Carbon Dioxide to Formate

“…ChemSusChem 2018ChemSusChem , 11,1656ChemSusChem -1663 www.chemsuschem.org curve for 1 MeCN )r emained almost constant at 1.53, which corresponded to the spin-only magnetic momento fm = 6.21;f rom 215 to 300 K, the spin-only value changed to m = 7.36. The above results were similart othose reported forhexacoordinated high-spinC o II complexes with N-donor ligands (m eff > 4.9m e ), [15] othert han low-spin hexacoordinated Co II complexes (m eff = 1.79-2.13 m B ). [16] Accordingt ot he equation, m ¼g ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffi s ðsþ1Þ p ,a nd the g value of 2.18 for 1 MeCN obtained from the solution electron paramagnetic resonance (EPR) spectrum (Figure 9a), the electron spin s value was calculated to be 3/2 for Co II ,c onsistent with high-spincobalt complexes.…”

Crystal structures, magnetic properties and DFT study of cobalt(II) azido complexes with the condensation product of 2-quinolinecarboxaldehyde and Girard’s T reagent

“…DFT calculated g-values for Co(II) complex 1 are summarized in Table 3. These results are similar to those reported for low-spin octahedral Co(II) complexes [33,36,43,52].…”

“…Obtained results show that Co(II) cation is in the low-spin state with t 2g 6 e g 1 (S = 1/2) configuration. Although it is known that octahedral Co(II) complexes prefer high-spin configuration, there are also some examples where low-spin configuration was observed [32][33][34][35][36]. This configuration can be expected only in a sufficiently strong ligand field which is required to create 2 E state of the free ion (t 2g 6 e g 1 configuration) from 2 G state (t Also, Figgis has found that spin-paired octahedral Co(II) complexes show the lowest magnetic moments, with very small orbital contribution, and close to spin-only value for S = 1/2, [39] which is in accordance with the obtained magnetic moment.…”

Trichloro(1,4,7-trithiacyclononane-S,S',S'')iron(III), [FeCl3(C6H12S3)]

“…The coordination chemistry of crown thioether ligands has received considerable attention recently from several laboratories (Wieghardt, Kiippers & Weiss, 1985;Kiippers, Wieghardt, Nuber, Weiss, Bill & Trautwein, 1987;Wilson, Swanson & Glass, 1986;Rawle, Timothy & Cooper, 1987). The small cyclic trithia crown ether 1,4,7-trithiacyclononane has been shown to be ideally suited for binding as a facially coordinated tridentate ligand to several different metal centers.…”