Eleftheria Agapaki a , Mukesh K. Singh a , Angelos B. Canaj a , Gary S. E-mail: ebrechin ed. E-mail: jschnack uni-bielefeld. Flexible N,O-bridging ligands have proved particularly successful in the construction of polymetallic clusters of Ni II displaying a variety of topologies and nuclearities, including supertetrahedra, 9 wheels, 10 planar discs 11 and icosahedra.
The asymmetric unit contains half the formula unit. The metallic skeleton of 1 is a single stranded [Ni II 14 ] wheel Fig. The HL 2 ligands and the formate ions originate from the in situ reaction of HL 1. The wheel is non-planar with nearest neighbour Ni II ions being above and below the plane running through the middle of the fourteen metal ions, i.
A search of the Cambridge Structural Database reveals that there are approximately thirty Ni wheels reported, ranging in nuclearity from [Ni 5 ] to [Ni 24 ].
Compound 1 also represents the first Ni II wheel built with 3,5-dimethylpyrazole or 1 H -pyrazole and indeed is the largest nuclearity Ni cluster known with either ligand.
The M vs. The addition of a next nearest neighbour interaction makes no difference to the quality of the simulation. Given that this interaction is computed to be very weak and ferromagnetic by DFT vide infra this is to be expected. Computational limitations direct us toward employing a [Ni 7 ] wheel, with the results multiplied by two to mimic the [Ni 14 ] wheel in order to assess the impact of anisotropy.
