Synthesis, Structures, and Single-Molecule Magnet Behaviour of High-Nuclearity Nickel(II) Dicubane-Type Complexes with Pyridyl-Alcohol Ligands

Chempluschem. 2015 Aug;80(8):1312-1320. doi: 10.1002/cplu.201500184. Epub 2015 Jul 3.

Abstract

The condensation reaction between two chemically different tetranuclear cubane-like clusters [Ni(μ3 -Cl)(Cl)(HL)]4 (1; HL=2-methyl-1-(pyridin-2-yl)propan-2-ol) and [Ni(μ3 -OH)(Cl)(HL)]4 (2) provides new access to higher nuclearity complexes, as shown with the synthesis of the octanuclear complex [Ni8 (μ3 -Cl)3 (μ3 -OH)5 (μ-Cl)2 Cl6 (HL)7 ] (3). In one instance, we also isolated the heptanuclear complex [Ni7 (μ3 -Cl)2 (μ3 -OH)6 Cl4 (H2 O)2 (HL)6 ]Cl2 (4). Magnetic properties measured by superconducting quantum interference device (SQUID) susceptometry evidenced S=8 and S=5 ground states for complexes 3 and 4, respectively. In particular, alternating current (ac) susceptometry evidenced slow relaxation of the magnetisation for complex 3, and suggests a similar behaviour at sub-kelvin temperatures for complex 4.

Keywords: N,O ligands; cluster compounds; cubanes; magnetic properties; nickel.