An original supramolecular helicate from a bipyridine-bipyrazine ligand strand and Ni-II by self-assembly
Résumé
A new discrete supramolecular pseudo-helicate has been obtained from a saturated heterotopic methylbipyrazyl-methylbipyridyl ligand strand and NiCl2. The X-ray structure of the dinuclear complex shows the 2-oxapropylene bridge oxygen atoms are engaged in coordination to the octahedral metal centre and a selective ligand inter-strand orientation is promoted in the complex. The crystal packing shows a perfect regular linear arrangement of the asymmetric units giving a packing of interacting molecules having well-defined rectangular and polygonal open channels. Although a paramagnetic behaviour is observed above 10 K, below this temperature a significant deviation of this behaviour suggests the presence of an Ni-II-Ni-II magnetic coupling.