Crystal and molecular structures of related nickel(II) complexes of open-chain and macrocyclic oxamide-based ligands and the peculiarities of water aggregates in their crystal lattices.

摘要: A comparison of the molecular structure related nickel(II) complexes open-chain and 13-membered macrocyclic oxamide-derived ligands NiL1·4H2O NiL2·3H2O revealed that formation an additional 6-membered chelate ring in complex results rather small changes bite angles around metal ion. Two deprotonated amide two amine donors form approximately square planar environment for both only essential consequence ligand cyclization is contraction nickel–nitrogen distances by 0.012 0.021 Ni–Namide Ni–Namine bonds, respectively. The packing modes NiL1 NiL2 crystalline state are essentially different—lattice water molecules isolated monomolecular 2D sheets separating gluing metallocomplex layers former complex, while they included hybrid metallocomplex–water connected van der Waals interactions latter. Analysis 1H NMR spectra reveals solid conformation retained aqueous solution.