Two isomorphous imidazole (Him) complexes: [MCl(2)(Him)(2)(H(2)O)(2)] (M = Co and Ni)

Area of Science:

• Coordination Chemistry
• Crystal Engineering
• Materials Science

Background:

• Metal complexes with imidazole ligands are of interest due to their diverse structural motifs and potential applications.
• Understanding the supramolecular assembly of coordination compounds is crucial for designing novel materials.

Purpose of the Study:

• To determine and compare the crystal structures of aquadichlorobis(1H-imidazole)cobalt(II) and aquadichlorobis(1H-imidazole)nickel(II) complexes.
• To investigate the role of hydrogen bonding in the formation of extended networks in these metal complexes.

Main Methods:

• Single crystal X-ray diffraction was employed to elucidate the molecular and crystal structures of the cobalt(II) and nickel(II) complexes.
• Analysis of intermolecular interactions, particularly hydrogen bonding, was performed to understand the network formation.

Main Results:

• The crystal structures of [CoCl(2)(Him)(2)(H(2)O)(2)] and [NiCl(2)(Him)(2)(H(2)O)(2)] were determined and found to be isomorphous.
• Both complexes exhibit monomeric units with inversion symmetry, featuring near-octahedral coordination geometries.
• Extensive hydrogen bonding networks involving imidazole and aqua ligands were observed, leading to a 3D supramolecular architecture.

Conclusions:

• The isomorphous nature of the cobalt(II) and nickel(II) complexes highlights the predictable structural behavior of these metal ions with imidazole.
• Hydrogen bonding plays a pivotal role in organizing these discrete molecular units into robust three-dimensional networks.
• The findings contribute to the understanding of crystal engineering principles in coordination chemistry.