Structural isomerism: linkage, coordination, ionisation, solvateसंरचनात्मक समावयवता: बंधनी, उपसहसंयोजन, आयनन, विलायकयोजनStructural isomerism: linkage, coordination, ionisation, solvate

NCERT §5.4.3–5.4.6 · Class 12 Chemistry · Chapter 5 · interactive diagram

Parts and what they mean

• Linkage isomerism (बंधनी समावयवता) — Needs an ambidentate ligand (NO₂⁻, SCN⁻). Discovered by Jørgensen.
• Red form: nitrito-O (लाल रूप: नाइट्रिटो-O) — Nitrite bound through oxygen (–ONO): pentaamminenitrito-O-cobalt(III) chloride.
• Yellow form: nitrito-N (पीला रूप: नाइट्रिटो-N) — Nitrite bound through nitrogen (–NO₂): pentaamminenitrito-N-cobalt(III) chloride.
• Coordination isomerism (उपसहसंयोजन समावयवता) — Both cation and anion are complexes; ligands are interchanged between the two metal ions.
• [Co(NH₃)₆][Cr(CN)₆] ([Co(NH₃)₆][Cr(CN)₆]) — NH₃ on Co³⁺, CN⁻ on Cr³⁺.
• [Cr(NH₃)₆][Co(CN)₆] ([Cr(NH₃)₆][Co(CN)₆]) — NH₃ on Cr³⁺, CN⁻ on Co³⁺ — its coordination isomer.
• Ionisation isomerism (आयनन समावयवता) — The counter ion is a potential ligand and can swap with a ligand; the isomers give different ions in water.
• [Co(NH₃)₅(SO₄)]Br ([Co(NH₃)₅(SO₄)]Br) — Gives free Br⁻: precipitate with Ag⁺ (AgBr), none with Ba²⁺ (NCERT intext answer 5.4).
• [Co(NH₃)₅Br]SO₄ ([Co(NH₃)₅Br]SO₄) — Gives free SO₄²⁻: precipitate with Ba²⁺ (BaSO₄), none with Ag⁺.
• Solvate (hydrate) isomerism (विलायकयोजन (हाइड्रेट) समावयवता) — Water is directly bonded to the metal in one isomer and free in the crystal lattice in the other.
• [Cr(H₂O)₆]Cl₃ — violet ([Cr(H₂O)₆]Cl₃ — बैंगनी) — All six water molecules are ligands; 3 Cl⁻ are free.
• [Cr(H₂O)₅Cl]Cl₂·H₂O — grey-green ([Cr(H₂O)₅Cl]Cl₂·H₂O — धूसर-हरा) — One Cl⁻ is now a ligand; one H₂O is outside as water of crystallisation.

Original diagram drawn by Simple Learning Hub, based on NCERT §5.4.3–5.4.6. Report a mistake