Complete the exercises below. Consider the following three complexes: (Complex 1) [Co(NH₃)₄Br₂]Cl (Complex 2) [Pd(NH₃)₂(ONO)₂] (Complex 3) [V(en)₂Cl₂]⁺. Which of the three complexes can have: a. geometric isomers, b. linkage isomers, c. optical isomers, d. coordination-sphere isomers?

Verified step by step guidance

1. Step 1: Identify the coordination number and geometry of each complex. For example, determine if the complex is octahedral, square planar, or tetrahedral based on the number of ligands and the metal center.
2. Step 2: Analyze each complex for geometric isomerism. Geometric isomers occur in complexes with specific geometries, such as octahedral or square planar, where ligands can occupy different positions relative to each other.
3. Step 3: Examine each complex for linkage isomerism. Linkage isomers arise when a ligand can bind to the metal center through different atoms. Check if any ligands in the complexes have multiple donor atoms.
4. Step 4: Investigate each complex for optical isomerism. Optical isomers are non-superimposable mirror images, which can occur in chiral complexes, often with bidentate ligands creating an asymmetrical arrangement.
5. Step 5: Consider coordination-sphere isomerism for each complex. Coordination-sphere isomers differ in the ligands directly attached to the metal versus those outside the coordination sphere, such as counterions.