Answer: [Co(en) 2 Cl 2 ]+ (cis form is chiral).
- A [Co(en)<sub>2</sub>Cl<sub>2</sub>]+ (cis form is chiral)
- B [Co(NH<sub>3</sub>)<sub>6</sub>]3+, a perfectly symmetric homoleptic complex with a plane of symmetry
- C [CoCl<sub>6</sub>]3-, a perfectly symmetric homoleptic complex with a plane of symmetry
- D trans-[Co(en)<sub>2</sub>Cl<sub>2</sub>]+, which possesses an internal mirror plane and is achiral
Correct answer: A. [Co(en)<sub>2</sub>Cl<sub>2</sub>]+ (cis form is chiral)
Explanation: The cis-[Co(en)<sub>2</sub>Cl<sub>2</sub>]+ has no plane of symmetry and shows Delta (right-handed) and Lambda (left-handed) enantiomers. The trans form has a plane of symmetry and is achiral.
The three common coordination geometries: octahedral (6 ligands), tetrahedral (4 ligands), and square planar (4 ligands in one plane).
Concept context
Study of compounds where a central metal atom is bonded to surrounding ligands. Covers nomenclature, types of isomerism, bonding theories (VBT, CFT), and applications in medicine, photography, and industry.