Paddlewheel dirhodium complexes bridged by para-substituted benzoates

Area of Science:

• Coordination Chemistry
• Crystallography
• Organometallic Chemistry

Background:

• Dirhodium complexes are versatile compounds with diverse applications in catalysis and materials science.
• Understanding their solid-state structures is crucial for predicting and controlling their reactivity and properties.

Purpose of the Study:

• To elucidate the crystal structures of two novel dirhodium(II) complexes.
• To investigate the intermolecular interactions governing their self-assembly in the solid state.

Main Methods:

• Single-crystal X-ray diffraction analysis was employed to determine the three-dimensional structures.
• Analysis of crystallographic data to identify hydrogen bonding and pi-pi stacking interactions.

Main Results:

• The bis(benzonitrile)tetrakis[mu-4-(diethylamino)benzoato-kappa2O:O']dirhodium(II) complex crystallizes with a disolvate, lying about an inversion center.
• The (methanol)tetrakis(mu-4-nitrobenzoato-kappa2O:O')(pyridine)dirhodium(II) complex forms dimers through O-H...O hydrogen bonding between axial methanol and carboxylate groups.
• Significant pi-pi stacking interactions were observed between bridging 4-nitrobenzoate ligands and axial pyridine ligands in the second complex.

Conclusions:

• The study highlights the importance of axial ligands and carboxylate groups in directing the self-assembly of dirhodium complexes in the solid state.
• The observed hydrogen bonding and pi-pi stacking interactions offer insights into crystal engineering strategies for dirhodium compounds.