How many unpaired electrons will there be in a high-spin octahedral complex of Fe(II)?
A) 0
B) 2
C) 4
D) 6
E) 8

Question

Quizplus · Accepted Answer

In a high-spin octahedral complex of Fe(II), there will be four unpaired electrons. This is because Fe(II) has six d-electrons, and in an octahedral field, the d-orbitals split into two sets: one with lower energy (e.g. dxy, dxz, and dyz) and the other with higher energy (e.g. dz2 and dx2-y2). In a high-spin complex, the electrons will occupy the lower-energy set of d-orbitals first, with one electron per orbital, before pairing up. Therefore, in Fe(II), the four remaining electrons will occupy four separate d-orbitals and remain unpaired.

How Many Unpaired Electrons Will There Be in a High-Spin