EAN Rule Doubts

Question

when EAN rule is obeyed?? only when it is 36??

Answer 1

Electron Atomic Number (EAN) rules are simply a different way of looking at the 18 electron rule. However, EAN rules are less general since they only pertain to the first row transition metals. In a nut shell, you are simply adding all the electrons of a complex metal and the electrons of ligands forming a coordinative covalent bond. Just like in the case of the 18 electron rule, this only tends to work for late transition metals (Fe --> Zn), although Mn, Cr and V in very low oxidation states can also follow this rule.