New dodecanuclear phenylphosphonate-bridged Co(II) complexes

New dodecanuclear phenylphosphonate-bridged Co(II) complexes [(μ2-THF)5(η-HPiv)Co12(μ3-OH)4(μ6-O3PPh)4(μ-Piv)12]·THF·2С6Н6 (1·THF·2С6Н6), [(μ2-THF)6Co12(μ3-OH)4(μ6-O3PPh)4(μ-Piv)12]·3THF (2·3THF) and [(μ2-Hmhp)6Co12(μ3-OH)4(μ6-O3PPh)4(μ-Piv)12]·6.5MeCN (3·6.5MeCN) have been synthesized by the reaction of the cobalt(II) pivalate polymer {Co(Piv)2}n (Piv is the pivalate anion), as a source of metal fragments containing cobalt(II) atoms, with potassium phenylphosphonate (K2PO3Ph) in the presence of neutral O-donor additional ligands like molecules of THF or 6-methyl-2-pyridone (Hmhp). The structures of the dodecanuclear complexes 1–3 were determined by using single-crystal X-ray diffraction data. The magnetic properties of the compounds showed that complexes 1 and 3 exhibit antiferromagnetic exchange interactions between the magnetic centers. The stability of compounds 1 and 3 were studied using thermogravimetric analysis.

Graphical abstractNew dodecanuclear complexes [(μ2-THF)5(η-HPiv)Co12(μ3-OH)4(μ6-O3PPh)4(μ-Piv)12]·THF·2С6Н6, [(μ2-THF)6Co12(μ3-OH)4(μ6-O3PPh)4(μ-Piv)12]·3THF and [(μ2-Hmhp)6Co12(μ3-OH)4(μ6-O3PPh)4(μ-Piv)12]·6.5MeCN were synthesized. The magnetic properties and thermal decomposition of the dodecanuclear complexes were studied.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Cobalt(II) pivalate polymer {Co(Piv)2}n. ► Cobalt(II) complexes [(μ3-L)6Co12(μ3-OH)4(μ6-O3PPh)4(μ-Piv)12] (L = THF, HPiv, Hmhp). ► The structures were determined by using single-crystal X-ray diffraction data. ► The magnetic properties and thermal decomposition of the synthesized complexes were investigated.