Coordination Compounds Part 2

(a) [CoCl2(en)2] shows cis-trans isomerism.
(b) [Co(CN)5(NC)]3− is of MA5B type complex, which will not show any isomerism.
(c) [Co(NH3)3(NO2)3] shows facial and meridonial isomerism.
(d) [Co(NH3)4Cl2]+ shows geometrical (cis-trans) isomerism. In cis
isomer, two Cl ligands are adjacent to each other. In trans
isomer two Cl ligands are opposite to each other.
∴ Option (b) is correct.