Question

The number and nature of d−d transition(s) in the case of Sc²⁺ in an octahedral crystal field, respectively, are
[Ignore spin-orbit coupling and Jahn-Teller distortion.]

• A. 1 and spin allowed.
• B. 3 and spin allowed.
• C. 1 and Laporte allowed.
• D. 3 and Laporte allowed

Answer 1

The Correct Option is A

For Sc²⁺, the electronic configuration is [Ar]3d¹, and the d-electrons are in the t_2g and e_g orbitals in an octahedral field.

1. The number of d-d transitions is determined by the number of unpaired electrons. In Sc²⁺, there is only one unpaired electron in the 3d¹ configuration, so only 1 transition is possible.
2. The nature of the transition is ”spin allowed” because a single electron can undergo a spin-flip transition without violating any selection rules.

Thus, the number and nature of d-d transitions for Sc²⁺ are 1 and spin allowed.

The correct answer is (A)