The Lanthanoids

In case of lanthanoids, 4f orbitals lie too deep and hence the magnetic effect of the motion of the electron in its orbital is not quenched out. Here spin contribution S and orbital contribution L couple together to give a new quantum number J. Thus magnetic moment of lanthanoids is given by, where J = L - S when the shell is less than half fill J = L + S when the shell is more than half fill and

The permanganate ion has an intense purple colour. Mn (+ VII) has a configuration. So the colour arises from charge transfer and not from d?d spectra.
In an electron is momentarily changing to and reducing the oxidation state of the metal from Mn(VII) to Mn (VI). Charge transfer requires that the energy levels on the two different atoms are fairly close.


hence the charge transfer occurs from