Cobalt and Nickel Oxide Architectures in Metal Carboxylate Frameworks: From Coordination Polymers to 3D Inorganic Skeletons

Abstract

This microreview is devoted to the synthesis and properties of nickel and cobalt polycarboxylates, which are classified in terms of the geometries of the organic moieties. It is divided into three main sections — dicarboxylates, tricarboxylates and tetra‐ and hexacarboxylates — and discusses the extreme diversity of these architectures. Numerous topologies can be obtained, ranging from coordination polymers to 3D inorganic skeletons. This microreview begins with the widely studied cobalt succinate system, for which, to date, seven compounds have been reported. Then, examples from malonate to pimelate illustrate the influence of the length of the organic ligand, whereas examples from fumarate to diphenate illustrate the effects of rigidity and complexity. In the same way, examples from trimesate to mellitate show the effects of “multiconnecting” organic partners. These latter seem to disadvantage metal oxide condensation, since the two 3D inorganic frameworks contain linear dicarboxylate ions. On the other hand, 3D nickel oxide skeletons seem to be easier to synthesise than cobalt ones. Moreover, under similar hydrothermal conditions, using cobalt and nickel generally leads to different architectures.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Synthesis, Crystal Structure, Magnetic, Thermal and Fluorescent Properties of [Co(H2O)4(nia)2](suc)·(H2suc)

“…It is known that the presence of infinite M-O-M connectivities in metal dicarboxylate structures enables the electronic and magnetic exchange in one, two 0932-0776 / 10 / 0600-0695 $ 06.00 c 2010 Verlag der Zeitschrift für Naturforschung, Tübingen · http://znaturforsch.com or three dimensions [1], but the M-O-C-O-M pathway also needs to be taken into account for weak coupling [16]. Furthermore, it has ben reported that magnetic exchange interactions through hydrogen bonds are also possible [17].…”

“…Furthermore, it has ben reported that magnetic exchange interactions through hydrogen bonds are also possible [17]. Because of the diversity of the inorganic networks and their complexity, metal carboxylate frameworks show different and usually extremely complicated magnetic behavior [16].…”

Effect of Mixing of Metal Cations on the Topology of Metal Oxide Networks

“…[16] These examples show that 3D inorganic MOFs are more specific to small, flexible carboxylates. [17] Previously, we studied relations between synthetic parameters (metal/succinate ratio, pH, concentration) and observed architectures for cobalt and nickel succinates. [17,18] In the case of cobalt, we demonstrated that condensation of the inorganic species increased with increasing temperature and pH, and this led to seven cobalt succinate topologies.…”

“…[17] Previously, we studied relations between synthetic parameters (metal/succinate ratio, pH, concentration) and observed architectures for cobalt and nickel succinates. [17,18] In the case of cobalt, we demonstrated that condensation of the inorganic species increased with increasing temperature and pH, and this led to seven cobalt succinate topologies. [18] Comparison of these compounds to known nickel succinates indicates that the phases that occur at lower temperatures tend to be isostructural (consistent with other Co II and Ni II coordination polymers) [19,20] while the hydrothermal phases differ significantly.…”

“…[5] Such layers were already observed for cobalt succinate and manganese glutarate. [17,27] Most of the structural characteristics of 3 correspond to features from either the more Co-rich 2, in which the sheets are identical, and Ni-rich 4, in which single octahedra connect sheets in the same way. The six crystallographically independent succinate anions act as scaffolds for the stability of the network.…”