Poly[copper(II)-mu-pyrazine-mu(3)-squarato].

Area of Science:

• Coordination Chemistry
• Crystal Engineering
• Materials Science

Background:

• Metal-organic frameworks (MOFs) offer tunable properties for diverse applications.
• Understanding the structure-property relationships in MOFs is crucial for designing new materials.
• Copper-squarate complexes represent an interesting class of MOFs with potential for unique functionalities.

Purpose of the Study:

• To elucidate the detailed crystal structure of the novel copper-squarate-pyrazine compound.
• To investigate the coordination environment of copper cations and the role of ligands in framework assembly.
• To characterize the supramolecular architecture and dimensionality of the resulting material.

Main Methods:

• Single-crystal X-ray diffraction analysis was employed to determine the precise atomic arrangement.
• Crystallographic data were collected and refined to establish the molecular and crystal structure.
• Analysis of coordination geometry and intermolecular interactions informed the structural description.

Main Results:

• The crystal structure reveals copper cations coordinated by three squarate (3,4-dihydroxy-3-cyclobutene-1,2-dioate) anions and two pyrazine ligands.
• Both the copper cation and squarate anions lie on a mirror plane, while pyrazine ligands are positioned around a perpendicular mirror plane.
• The coordination leads to the formation of extended two-dimensional sheets parallel to the (001) crystallographic plane.

Conclusions:

• The compound exhibits a unique layered structure driven by specific coordination preferences of copper with squarate and pyrazine.
• The observed structural motif highlights the versatility of squarate and pyrazine as bridging ligands in constructing coordination polymers.
• This detailed structural understanding provides a foundation for exploring the physical and chemical properties of this copper-based material.