[timchai]

Determine the oxidation number(s) of the ruthenium in the Creutz-
Taube complex, and show your reasoning

ans:Ru is in the same group as iron, so Ru has a 4d6, 5s2 electronic
structure.
It has two oxidation states: +2 (4d6, 5s0) and +3 (4d5, 5s0). Oxidation
numbers of the two atoms in the Creutz-Taube complex are +2 and +3
respectively.

can u explain ,how about Fe (H2O)2+ using this method ,the O.N. i think we can use original method just use O.N of pyrine +...= total O.N. of compund

[Borek]

There is no such thing as ON of compound. Compound can have charge only.

If complex contains neutral molecule (like NH₃) ignoring the molecule you will not change ON calculations for whatever is left. You can strip the complex of almost everything.

ON is just an accounting device, it doesn't reflect any real, measurable property of the matter. 2x2.5 if you ask me.