New 2D Coordination Polymer of Cobalt(II) Pivalate with 1,4-Diaminobutane: Synthesis and Thermal Properties

The reaction of cobalt(II) trimethyl acetate (pivalate) [Co(Piv)2]n (HPiv = HO2CCMe3) with 1,4-diaminobutane (Dab) in absolute acetonitrile gave a 2D-coordination polymer [Co(Piv)2(Dab)2]n (I) with an admixture of the co-product, but the addition of one equivalent of 2,2'-bipyridine to the reaction mixture made it possible to isolate a single-phase sample of I (according to X-ray diffraction data) with a yield of 78%. The crystal structure of I was determined by X-ray diffraction (CCDC No. 2404406): cobalt(lI) atoms in a distorted octahedral environment (CoN4O2) of two monodentate carboxylate groups and four bridging Dab molecules form a layered coordination polymer with a honeycomb-like hcb topology. The thermal behavior of I was studied by synchronous thermal analysis: thermal decomposition leads to the formation of the organic salt (H2Dab)(Piv)2, cobalt(II) pivalate, and the octanuclear complex [Co8O2(Piv)12] - the products were identified by XRD and NMR spectroscopy.