Question

Consider the following statements for [Ni(dmg)$_2$]: (A) It is a red coloured compound.
(B) It is readily soluble in water at pH = 9.
(C) Central metal ion has two unpaired electrons.
(D) It has four, 5-membered metal containing rings.

• A. A and D are correct
• B. B, C and D are incorrect
• C. A, C and D are correct
• D. A, B, C, D are incorrect

Hint:

When analyzing metal-ligand complexes, be aware of their solubility and color based on the coordination environment and the oxidation state of the metal ion.

Answer 1

The Correct Option is B

Step 1: Understanding the compound.
[Ni(dmg)$_2$] is a nickel complex where the nickel ion is coordinated with two dmg ligands. The Ni$^{2+}$ ion has two unpaired electrons, making the compound paramagnetic, and it typically has a greenish color, not red.
It is not readily soluble in water at pH = 9, which is a typical property of many nickel complexes with ligand coordination. The central metal ion does not have four, 5-membered metal containing rings.
Step 2: Conclusion.
Thus, statements B, C, and D are incorrect, and the correct answer is (2).