Unit V: Coordination Chemistry - Online Test

Three isomers. If we consider any one of the ligands as reference ( say Py), the arrangement  of other three ligands ( NH₃, Br and Cl^‑ ) with respect to (Py) gives three geometrical isomers.

(a) coordination isomers

(b) no isomerism ( different molecular formula)

(c) ← NCS , ← SCN coordinating atom differs : linkage isomers

Option (a) and (b) – geometrical isomerism is possible

Option (c) – ionization isomerism is possible

Option (d) – no possibility to show either constitutional isomerism or stereo isomerism

(a) Fe²⁺

(b) Fe³⁺

(c) Fe⁰

(a) Zn²⁺ (d¹⁰ ⟹ diamagnetic)

(b) Co³⁺ (d⁶ Low spin ⟹ t₂g⁶, e_g⁰ diamagnetic)

(c) Ni²⁺ (d⁸ Low spin ⟹ t₂g⁶, e_g² paramagnetic)

(d) [Ni(CN)₄]^2- (dsp2 ; square planar, diamagnetic)

V²⁺ ( t₂g³, e_g⁰ ; CFSE = 3 x (-0.4)Δ₀ = -1.2 Δ₀)

Ti²⁺ ( t₂g², e_g⁰ ; CFSE = 2 x (-0.4)Δ₀ = -0.8 Δ₀)

Statements given in option (a) ,(b), and (c) are wrong.

The current statements are

(a) since, the crystal field stabilization is more in octahedral field , octahedral complexes are more stable than square planar complexes.

(b)