Structural, electronic, and magnetic properties of Con(benzene)m complexes

Area of Science:

• Computational chemistry
• Materials science
• Quantum mechanics

Background:

• Cobalt-benzene complexes are of interest for their unique structural, electronic, and magnetic properties.
• Understanding the relationship between structure and magnetism in these clusters is crucial for potential applications.

Purpose of the Study:

• To investigate the structural, electronic, and magnetic properties of cobalt-benzene complexes (Co(n)Bz(m)).
• To determine the preferred conformations and stability of these complexes.
• To correlate computed properties with experimental measurements.

Main Methods:

• Utilizing all-electron gradient-corrected density functional theory (DFT).
• Exploring various cluster sizes and compositions (n, m = 1-4, m = n, n + 1).
• Analyzing binding energies, HOMO-LUMO gaps, ionization potentials, and magnetic moments.

Main Results:

• Sandwich conformations are favored for small complexes (n, m = 1-2), while rice-ball structures dominate for larger sizes (n >= 3).
• Both motifs coexist for Co(2)Bz(3); rice-ball clusters (3,3) and (4,4) are more stable than (3,4).
• Computed properties align well with experimental data, suggesting measured magnetic moments are averages of mixed isomers.

Conclusions:

• Benzene molecules play an attenuating role in the magnetism of cobalt clusters.
• Ferromagnetic ordering is preferred for smaller complexes (n=1-3), while antiferromagnetic ordering is favored for (4,4).
• The study provides insights into the structure-property relationships of cobalt-benzene complexes.