An octahedral coordination complex has a spin-only magnetic moment of 1.73 BM and a crystal field stabilization energy (CFSE) of -2.0 _o (ignoring pairing energy). Which of the following complexes matches these properties?

Step-by-step solution

A spin-only magnetic moment of 1.73 BM implies the presence of exactly 1 unpaired electron, since = n(n+2) BM gives n = 1 . The CFSE for an octahedral complex is given by (-0.4 x + 0.6 y) _o , where x is the number of electrons in the t _ 2 g orbitals and y is the number of electrons in the e _ g orbitals. For the CFSE to be -2.0 _o , we must have 5 electrons in the t _ 2 g level and 0 in the e _ g level (since 5 -0.4 = -2.0 ). This corresponds to a t _ 2 g ^5 e _ g ^0 configuration, which is a 3 d ^5 low-spin stat