[_rob]

Right so my question begins with the complex [MoH4(Ph2PCh2Ch2PPh2)2]2+, and the question goes on to say what is the oxidation state change when this is protonated? My logic would say that as a proton is H+, both bonding electrons must come from the metal ion, which would suggest an oxidation state of 4+ to 6+, firstly, is this correct?

Secondly the question asks why the complex can't be protinated again, and using the same logic, I would say that Mo's last two valence electrons were used to form the bond with the first proton, and therefore it has no more electrons to use for bonding and therefore cannot be oxidised any more, 6+ is it's maximum oxidation state.

Could anybody tell me whether this is correct, and if not, where I am going wrong?

Help much appreciated,

Rob