Tetrahedral complexes are generally high spin. This is because :
Tetrahedral complexes are generally high spin. This is because :
The correct option is
D
Δt<p
The splitting of tetrahedral complexes is, in a way, the direct opposite of the splitting of the octahedral complexes. In octahedral complexes, the dz2 and dx2−y2 orbitals have higher energy than the dxz,dxy, and dyz orbitals. In tetrahedral complexes, dxz,dxy, and dyz orbitals have higher energy than the dz2 and dx2−y2 orbitals. In tetrahedral complexes, the contact between the ligands and the orbitals is reverse that of octahedral complexes. Unlike octahedral complexes, the ligands of tetrahedral complexes come in direct contact with the dxz,dxy, and dyz orbitals. Thus, these orbitals have high electron-electron repulsion, due to the direct contact, and thus higher energy. The dz2 and dx2−y2 orbitals do not have as direct contact as the ligands kind of squeeze past or slide by these orbitals, thus lowering the electron-electron repulsion and the energy of the orbital.
In a tetrahedral complex, Δt is relatively small even with strong-field ligands as there are fewer ligands to bond with. It is rare for the Δt of tetrahedral complexes to exceed the pairing energy. Usually, electrons will move up to the higher energy orbitals rather than get paired. In view of these factors, most tetrahedral complexes are high spin.
The correct option is
D
Δt<p
The splitting of tetrahedral complexes is, in a way, the direct opposite of the splitting of the octahedral complexes. In octahedral complexes, the dz2 and dx2−y2 orbitals have higher energy than the dxz,dxy, and dyz orbitals. In tetrahedral complexes, dxz,dxy, and dyz orbitals have higher energy than the dz2 and dx2−y2 orbitals. In tetrahedral complexes, the contact between the ligands and the orbitals is reverse that of octahedral complexes. Unlike octahedral complexes, the ligands of tetrahedral complexes come in direct contact with the dxz,dxy, and dyz orbitals. Thus, these orbitals have high electron-electron repulsion, due to the direct contact, and thus higher energy. The dz2 and dx2−y2 orbitals do not have as direct contact as the ligands kind of squeeze past or slide by these orbitals, thus lowering the electron-electron repulsion and the energy of the orbital.
In a tetrahedral complex, Δt is relatively small even with strong-field ligands as there are fewer ligands to bond with. It is rare for the Δt of tetrahedral complexes to exceed the pairing energy. Usually, electrons will move up to the higher energy orbitals rather than get paired. In view of these factors, most tetrahedral complexes are high spin.
