Trigonal crystal system

Nuclear magnetic resonance

Crystal structure

Atomic physics

Molecule

Jahn–Teller effect

Mathematical optimization

Hamiltonian (control theory)

Electron paramagnetic resonance

Physics

Organic chemistry

Mathematics

Molecular physics

Ligand field theory

Computational chemistry

Tetrahedron

Crystallography

Chemistry

Tetrahedral molecular geometry

Molecular Physics

The perturbation formulas of the spin Hamiltonian parameters (zero-field splitting and g factor g// and g⊥) are established for a 3d8 ion in trigonally distorted tetrahedra for the first time. In the theoretical treatments, the contributions from the Jahn–Teller effect, the ligand orbital and spin–orbit coupling interactions and configuration interactions are taken into account from the cluster approach in a uniform way. The above formulas are applied to the studies of the spin Hamiltonian parameters for the three CoCl(PPh3)3 molecules, and the experimental electron paramagnetic resonance spectra of all the molecules are satisfactorily explained. The significant compressions of the ligand tetrahedra with mixed chlorine and PPh3 groups around Co+ are analysed for three distinct CoCl(PPh3)3 compounds, characterised by the Cl–Co–P bond angles θ larger than the tetrahedral angle of 109.47°. The local trigonal distortions are discussed in view of the Jahn–Teller effect.

Theoretical investigations of the spin Hamiltonian parameters for the CoCl(PPh<sub>3</sub>)<sub>3</sub>molecules

Theoretical investigations of the spin Hamiltonian parameters for the CoCl(PPh3)3molecules

Theoretical investigations of the spin Hamiltonian parameters for the CoCl(PPh₃)₃molecules