Answer: Five (cis and trans geometric isomers, with the cis form giving three: two cis diastereomers of en orientation and optical isomers).
- A Five (cis and trans geometric isomers, with the cis form giving three: two cis diastereomers of en orientation and optical isomers)
- B Just two isomers in total, counting mainly a single cis form and a single trans form according to conventional understanding in routine practice
- C Exactly three isomers in total, largely ignoring any optical activity within the cis form overall in most cases under typical conditions
- D Mainly one single possible isomer, since the en ligand is said to fix a unique overall geometry according to standard textbooks
Correct answer: A. Five (cis and trans geometric isomers, with the cis form giving three: two cis diastereomers of en orientation and optical isomers)
Explanation: This type of complex is complex enough for JEE: cis and trans geometric isomers exist; the cis isomer can have en coordinating in different ways and may show optical isomerism.
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.