when the negative field is due to ligands in a complex it becomes asymmetrical and degeneracy of d orbitals is lifted. What does it mean?
when the negative field is due to ligands in a complex it becomes asymmetrical and degeneracy of d orbitals is lifted. What does it mean?
In an isolated gaseous metal atom or an ion, all the 5 d orbitals are degenerate that is they have the same energy. This degeneracy is maintained if a spherically symmetrical field of negative charges surrounds the metal atom/ion. In other words, if negative charges surround the metal ion then the electric field due to these negative charges is symmetrical (equal in all directions). The d-orbitals would be raised in energy, but all five of them will continue to have equal energy. However, when complex formation takes place, then this negative field due to ligands (either anions or the negative ends of dipolar molecules like NH3 and H2O) becomes unequal or asymmetrical. As a result, the 5 d orbitals no longer possess equal energy. Some will have higher energy and some will have lower energy. In other words, the degeneracy of the d-orbitals is removed.
In an isolated gaseous metal atom or an ion, all the 5 d orbitals are degenerate that is they have the same energy. This degeneracy is maintained if a spherically symmetrical field of negative charges surrounds the metal atom/ion. In other words, if negative charges surround the metal ion then the electric field due to these negative charges is symmetrical (equal in all directions). The d-orbitals would be raised in energy, but all five of them will continue to have equal energy. However, when complex formation takes place, then this negative field due to ligands (either anions or the negative ends of dipolar molecules like NH3 and H2O) becomes unequal or asymmetrical. As a result, the 5 d orbitals no longer possess equal energy. Some will have higher energy and some will have lower energy. In other words, the degeneracy of the d-orbitals is removed.
