Question

The geometry of [VO(acac)₂] is

• A. square pyramidal
• B. trigonal bipyramidal
• C. pentagonal planar
• D. distorted trigonal bipyramidal

Answer 1

The Correct Option is A

The problem involves determining the geometry of the complex [VO(acac)₂]. To solve this, we need to consider the coordination environment and ligand arrangement around the central metal ion in the complex.

Step 1: Analyzing the Complex

• The central metal ion in this complex is vanadium (V).
• Vanadium is in the +4 oxidation state here, commonly represented as V⁴⁺.
• The complex also contains two acetylacetonate (acac) ligands. Each acac ligand is a bidentate ligand, which means each ligand forms two bonds with the vanadium center, leading to a total of four coordination sites occupied.

Step 2: Understanding the Geometry

• With the acac ligands contributing four coordination sites, there is typically one more bond formed by an oxo group (O) to reach a typical coordination number of 5, which is common for vanadium in this oxidation state.
• The typical geometries for complexes with coordination number 5 are trigonal bipyramidal and square pyramidal. The presence of an oxo group and symmetrical bidentate ligands usually stabilizes the square pyramidal geometry.

Step 3: Determination of Geometry

• In the case of [VO(acac)₂], the structure is such that the oxo group takes an apical position in a square pyramidal geometry.
• Therefore, the most stable and favorable geometry for [VO(acac)₂] is square pyramidal.

Conclusion:

Based on the coordination number and the type of ligands present, the geometry of the [VO(acac)₂] complex is square pyramidal. Thus, the correct answer is the option "square pyramidal". This arrangement minimizes electronic repulsions and provides a stable structure for the complex.