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Gold-gold interactions as crystal engineering design elements in heterobimetallic coordination polymers
D B Leznoff1, B Y Xue, R J Batchelor
1Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6 Canada. dleznoff@sfu.ca
Inorganic Chemistry
|October 30, 2001
Summary
Coordination polymers with copper and gold cyanide units demonstrate the power of aurophilic interactions in building complex supramolecular structures. These gold-gold bonds increase structural dimensionality, leading to diverse 1D, 2D, and 3D networks.
Area of Science:
- Supramolecular Chemistry
- Coordination Chemistry
- Materials Science
Background:
- Coordination polymers offer tunable properties based on metal centers and ligands.
- Aurophilic interactions (gold-gold bonds) are increasingly recognized for their role in stabilizing and structuring materials.
- Understanding the influence of these interactions is key to designing novel supramolecular architectures.
Purpose of the Study:
- To synthesize and characterize coordination polymers incorporating Cu(II) and [Au(CN)2]− units.
- To investigate the role of aurophilic interactions in dictating the dimensionality and structure of these polymers.
- To compare the structural and bonding characteristics with analogous silver(I) systems.
Main Methods:
- Synthesis of coordination polymers using various copper(II) complexes and [Au(CN)2]−.
- Single-crystal X-ray diffraction analysis to determine detailed structures.
- Bond length analysis (Au-Au, M-C) and magnetic susceptibility measurements.
Main Results:
- A series of coordination polymers with diverse dimensionalities (1D, 2D, 3D) were successfully prepared.
- Aurophilic interactions were identified as crucial for increasing structural dimensionality, observed in multiple complexes.
- Complex 2-Au exhibited shorter Au-Au bonds than its silver analog, and shorter Cu-Au cyanide bonds, indicating smaller Au(I) size compared to Ag(I).
- Complex 5 displayed an unusual 2D rhombohedral layer structure with interpenetrating networks linked by aurophilic interactions.
- Weak antiferromagnetic coupling was observed in complexes 2 and 5.
Conclusions:
- Aurophilic interactions are powerful directing forces for constructing complex supramolecular architectures with varying dimensionalities.
- The study highlights the significant role of gold-gold bonding in the self-assembly of coordination polymers.
- The findings provide insights into the comparative size of Au(I) and Ag(I) based on M-C bond lengths.
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