Number of possible isomers for the complex [Co(en)2Cl2]Cl will be (en = ethylenediamine)
- 1
- 3
- 4
- 2
Answer
(2) 3
Solution
[Co(en)2Cl2]+ is an octahedral complex of type [M(AA)2B2].
It shows geometrical isomerism: cis and trans forms.
∵ The trans isomer has a plane of symmetry, it is optically inactive.
∵ The cis isomer has no plane of symmetry, it exists as a pair of enantiomers (d and l).
As per NCERT, [CoCl2(en)2]+ gives trans + two optically active cis forms.
∴ Total isomers = 1 + 2 = 3
Answer: (2)