# Order of priority in hybridization of d-orbitals

During hybridization of d-orbitals why the $d_{z^2}$ and $d_{x^2-y^2}$ orbitals are used up before the $d_{xy}$, $d_{yz}$ and $d_{zx}$ ?

• Do you mean dx^2- y ^2 ? – Rajesh Mar 25 '15 at 17:11
• Yes. Sorry, typing error – Dhruba Banerjee Mar 25 '15 at 17:13
• d-orbitals are used up in what? Complex formation? Can you add a source for this statement? – Rajesh Mar 25 '15 at 17:15
• In hybridizations. sp3, sp2 etc – Dhruba Banerjee Mar 25 '15 at 17:17
• I think VBT doesnt distinguish between the d-orbitals while CFT does. – Rajesh Mar 25 '15 at 17:38

The rotational frame of reference which defined which axis is the z-axis is changed such that $d_{z^2}$ and $d_{x^2-y^2}$ are hybridized first is a convention / practice.