Mononuclear Mn(II), Co(II), and Cu(II) pivalates

Mononuclear Mn(II), Co(II), and Cu(II) pivalates were synthesized for the first time. They were isolated as salts with a composition NBu4[MPiv3], where Piv is the pivalate anion. In the structure of the [MnPiv3] and [CoPiv3] coordination units, the environment of the central atom was found to be close to a trigonal prism. In [CuPiv3], the distorted square environment of Cu is formed by one bidentate O,O′-Piv and two monodentate Piv’s; the second O atoms of monodentate Piv’s tend to occupy the positions close to the apical positions of the elongated octahedron. An X-ray diffraction study of NBu4[CoPiv3] and NBu4[CuPiv3] crystals showed strong disordering of the O atoms of the coordinated carboxylate groups at room temperature, which was suppressed when NBu4[CoPiv3] was cooled to 85 K and NBu4[CuPiv3] to 30 K. In the synthesis of NBu4[CoPiv3] and NBu4[CuPiv3], new compounds, namely, tetranuclear (NBu4)2[Co4Piv8(AcO)2(H2O)4] and (NBu4)2[Cu4Piv8(AcO)2(H2O)2], respectively, formed along with the major product.

Mononuclear pivalates NBu4[MPiv3], where M is Mn(II), Co(II), or Cu(II), were isolated. It was found that the chelate coordination of all pivalates led to an environment of the central atom that was close to a trigonal prism in [MnPiv3] and [CoPiv3] and transformed into a distorted square environment in [CuPiv3].Figure optionsDownload as PowerPoint slide