Twinned dichlorobis(2,6-dichloropyrazine-N(4))zinc(II)

Area of Science:

• Crystal chemistry
• Coordination chemistry
• Solid-state chemistry

Background:

• The title compound, [ZnCl(2)(C(4)H(2)Cl(2)N(2))(2)], was synthesized and subjected to crystallographic analysis.
• Preliminary metric considerations suggested a monoclinic unit cell for the crystals.

Purpose of the Study:

• To determine the precise crystal structure of [ZnCl(2)(C(4)H(2)Cl(2)N(2))(2)].
• To investigate the crystallographic symmetry and identify any twinning phenomena.
• To analyze the molecular coordination and packing within the crystal lattice.

Main Methods:

• Single-crystal X-ray diffraction was employed to collect diffraction data.
• Crystallographic data were analyzed to determine the unit cell parameters and space group.
• Structure solution and refinement were performed to establish the atomic arrangement.

Main Results:

• The diffraction pattern symmetry indicated a triclinic crystal system, differing from the suggested monoclinic metric symmetry.
• All examined crystals were found to be twinned, with the discrepancy in reliability indices providing insight into the volume ratio of the twin components.
• The asymmetric unit contains three independent molecules, each featuring a distorted tetrahedral coordination around the central zinc (Zn) atom.

Conclusions:

• The crystal structure of [ZnCl(2)(C(4)H(2)Cl(2)N(2))(2)] is triclinic, not monoclinic as initially suggested by metric considerations.
• Crystal twinning is a significant feature of this compound, influencing the interpretation of diffraction data.
• The molecular structure is characterized by distorted tetrahedral zinc coordination, with three independent molecules present in the asymmetric unit.