A d⁶ ion (Fe²⁺) is complexed with six strong-field ligands (for example, SCN^-). What is the number of unpaired electrons in this complex? A) 3 B) 2 C) 0 D) 1 E) 4

Question

Quizplus · Accepted Answer

The complex has an octahedral geometry as there are six ligands present. The iron ion in the complex is of d6 configuration, meaning it has 6 d-electrons in the 3d subshell. The six strong-field ligands will pair up all the d-electrons to form three d-orbitals with pairs of electrons in them. Therefore, there are no unpaired electrons, giving a total spin state of S=0. Thus, the answer is C.

A D6 Ion (Fe2+) Is Complexed with Six Strong-Field Ligands

A D⁶ Ion (Fe²⁺) Is Complexed with Six Strong-Field Ligands