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Question #44604

Difficulty: 8/10 | 🟢 Free

The Question

Among the 3d transition metals, there exists a unique, neutral, mononuclear homoleptic metal carbonyl complex $\ce{M(CO)_x}$ that is paramagnetic at 298 K and 1 atm, defying the 18-electron rule. It resists dimerization due to severe steric crowding. Based on Crystal Field Theory and synergic bonding principles, determine the spin-only magnetic moment ( $\mu_{spin}$ ) of this complex and the crystal field electronic configuration of the metal center.

Options

A.
$1.73 \text{ BM}, t_{2g}^5 e_g^0$
B.
$0.00 \text{ BM}, t_{2g}^6 e_g^0$
C.
$3.87 \text{ BM}, t_{2g}^3 e_g^2$
D.
$1.73 \text{ BM}, e^4 t_2^1$

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Mechanism_Trap

Don't get tricked by the process! Learn the mechanical traps used in competitive exam questions.

Concepts Behind This Question

Synergic Bonding in Carbonyls|Spin-Only Magnetic Moment|Tetrahedral Splitting Patterns

Why This Question Is Tricky

Common Mistakes

This problem tests the intersection of the 18-electron rule, synergic bonding, and Crystal Field Theory.

The primary trap is the 'Low Spin = Diamagnetic' heuristic.

Students often assume all metal carbonyls dimerize to achieve 18 electrons (Option B).

The secondary trap exploits the 'Tetrahedral vs Octahedral' geometry; students might incorrectly assume a tetrahedral geometry (like $\ce{Ni(CO)_4}$ ) and force a strong-field splitting to get 1 unpaired electron (Option D), ignoring that $\ce{V(CO)_6}$ is strictly octahedral.

Quick Facts About This Question

Question Information

Subject	Chemistry
Chapter	Coordination Compounds - Class 12
Concept	Synergic Bonding in Carbonyls
Difficulty	8
Cognitive Load	7
Target Solve Time	160 sec
Access	Free