Question

Total number of the geometrical isomers in complex I and II are x and total number of optical isomers in Complex I and II are y. The value of (x + y) is _____

Answer 1

15

Answer 2

Complex (I) [Pt(NH3)2(Py)2 Br2]2+ is interpreted as an octahedral complex of the type [MA2B2C2]. It has 5 geometrical isomers. The optical isomers are:

• A-A (trans), B-B (cis), C-C (cis): Achiral (0 optical isomers)
• A-A (trans), B-B (trans), C-C (trans): Achiral (0 optical isomers)
• A-A (cis), B-B (cis), C-C (cis): Chiral (2 optical isomers)
• A-A (cis), B-B (cis), C-C (trans): Chiral (2 optical isomers)
• A-A (cis), B-B (trans), C-C (trans): Chiral (2 optical isomers) Total optical isomers for Complex (I) = $0 + 0 + 2 + 2 + 2 = 6$.

Complex (II) [Co(en)2CIBr]+ is an octahedral complex of the type [M(AA)2BC]. The 'en' ligand is bidentate.

• Geometrical Isomers:
  • Cl and Br are trans: 1 isomer (achiral).
  • Cl and Br are cis: 1 isomer (chiral). Total geometrical isomers for Complex (II) = $1 + 1 = 2$.
• Optical Isomers:
  • The trans isomer is achiral (0 optical isomers).
  • The cis isomer is chiral (2 optical isomers). Total optical isomers for Complex (II) = $0 + 2 = 2$.

Total number of geometrical isomers (x) = Geometrical isomers of (I) + Geometrical isomers of (II) = $5 + 2 = 7$. Total number of optical isomers (y) = Optical isomers of (I) + Optical isomers of (II) = $6 + 2 = 8$.

The value of (x + y) = $7 + 8 = 15$.