Bis(guanidinium) tetra-iodidomercurate(II)

Area of Science:

• Inorganic Chemistry
• Crystal Structure Analysis
• Solid-State Chemistry

Background:

• Guanidinium salts and metal halides are important classes of compounds with diverse applications.
• Understanding the coordination chemistry and intermolecular interactions in such compounds is crucial for materials science.

Purpose of the Study:

• To elucidate the crystal structure of the title compound, (CH(6)N(3))(2)[HgI(4)].
• To investigate the coordination environment of the mercury atom and the nature of intermolecular interactions.
• To correlate crystallographic data with spectroscopic findings, specifically (127)I Nuclear Quadrupole Resonance (NQR) frequencies.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the three-dimensional crystal structure.
• Analysis of bond distances and coordination geometry around the mercury (Hg) atom.
• Measurement and analysis of (127)I NQR frequencies.

Main Results:

• The crystal structure shows a mercury atom tetrahedrally coordinated by four iodine atoms within the [HgI(4)](2-) anion.
• The [HgI(4)](2-) anions and [C(NH(2))(3)](+) cations form a three-dimensional network through N-H⋯I hydrogen bonds.
• Four distinct Hg-I bond lengths were observed, ranging from 2.760(2) to 2.833(2) Å, consistent with four unique iodine atoms.

Conclusions:

• The crystallographic and (127)I NQR data confirm the presence of four unique iodine atoms in the tetraiodomercurate unit.
• The study highlights the role of hydrogen bonding in stabilizing the overall three-dimensional crystal structure.
• This detailed structural characterization provides a foundation for understanding the properties and potential applications of this guanidinium tetraiodomercurate compound.