Bis(1,5-diazacyclooctane-N,N')nickel(II) dibromide

Area of Science:

• Inorganic Chemistry
• Crystallography
• Coordination Chemistry

Background:

• Nickel(II) complexes are widely studied for their diverse coordination geometries and applications.
• Macrocyclic ligands, such as 1,5-diazacyclooctane (DACO), offer unique binding properties to metal ions.
• Understanding the precise crystal structure of metal complexes is crucial for predicting their chemical behavior.

Purpose of the Study:

• To elucidate the crystal structure of the [Ni(DACO)2]Br2 complex.
• To characterize the coordination environment and geometry of the Ni(II) ion.
• To investigate the interactions between the complex cation and bromide counter-anions.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the crystal structure.
• Analysis of bond lengths, bond angles, and coordination geometry.
• Identification of intermolecular interactions, such as hydrogen bonding.

Main Results:

• The crystal structure consists of discrete [Ni(DACO)2](2+) cations and bromide anions.
• The Ni(II) ion exhibits a square planar coordination geometry, coordinated by four nitrogen atoms from two DACO ligands.
• The Ni-N bond lengths were determined to be within the range of 1.935–1.937 Å.
• Both DACO ligands adopt a boat-chair conformation.
• Bromide anions form hydrogen bonds with the nitrogen donors of the DACO ligands, creating a macrocycle-like ring system.

Conclusions:

• The study provides a detailed structural characterization of the [Ni(DACO)2]Br2 complex.
• The square planar geometry and specific ligand conformation are key features of this nickel(II) complex.
• The observed hydrogen bonding highlights the supramolecular assembly in the crystal lattice.