octaimelda - 22-4-2012 at 20:15
why sodium peroxide have diamagnetic properties, but calsium superperoxide, has paramagnetic properties? Thank you.
barley81 - 23-4-2012 at 02:48
I assume you mean calcium superoxide.
Sodium peroxide is diamagnetic because all electrons are paired. You may draw an MO diagram if you like. That way the anti bonding pi orbitals, which
are both half-filled in dioxygen, are now completely filled. This results in the pairing of all electrons and a total bond order of 1. Therefore it's
diamagnetic (sodium + has all e paired as well)
In the superoxide ion, there is one unpaired electron. One of the pi anti bonding orbitals is completely filled, and the other is half-filled. This
results in a bond order of 1.5. Superoxide is therefore paramagnetic due to unpaired electrons.