Types of ligands: uni-, di-, poly- and ambidentateलिगन्ड के प्रकार: एकदंतुर, द्विदंतुर, बहुदंतुर, उभयदंतीTypes of ligands: uni-, di-, poly- and ambidentate

NCERT §5.2(c) · Class 12 Chemistry · Chapter 5 · interactive diagram

Parts and what they mean

• Unidentate ligands (एकदंतुर लिगन्ड) — Bind through a single donor atom: Cl⁻, H₂O, NH₃ (NCERT examples).
• NH₃ — ammine (NH₃ — ऐम्मीन) — Neutral; donor atom N. In names it is “ammine” (double m).
• H₂O — aqua (H₂O — ऐक्वा) — Neutral; donor atom O. Named “aqua”.
• Cl⁻ — chlorido (Cl⁻ — क्लोरिडो) — Anionic (−1); anionic ligand names end in -o (chlorido).
• CN⁻ — cyanido (CN⁻ — सायनिडो) — Anionic (−1), binds through C; a strong-field ligand.
• Didentate ligands (द्विदंतुर लिगन्ड) — Bind through two donor atoms at the same time, e.g. en and oxalate.
• en — ethane-1,2-diamine (en — एथेन-1,2-डाइऐमीन) — H₂N–CH₂–CH₂–NH₂: neutral, two N donors → forms a 5-membered chelate ring with the metal.
• Oxalate C₂O₄²⁻ — oxalato (ऑक्सेलेट C₂O₄²⁻ — ऑक्सेलेटो) — Charge −2; binds through two O atoms (didentate).
• Polydentate ligands (बहुदंतुर लिगन्ड) — Several donor atoms in one ligand.
• N(CH₂CH₂NH₂)₃ (N(CH₂CH₂NH₂)₃) — NCERT’s example of a polydentate ligand: four N donor atoms.
• EDTA⁴⁻ — hexadentate (EDTA⁴⁻ — षट्दंतुर) — Ethylenediaminetetraacetate binds through two N and four O atoms. Used to estimate hardness of water and to treat lead poisoning.
• Ambidentate ligands (उभयदंती लिगन्ड) — Have two different donor atoms but bind through only one of them at a time: NO₂⁻ and SCN⁻.
• NO₂⁻ through N: nitrito-N (N से NO₂⁻: नाइट्रिटो-N) — M–NO₂. Gives the yellow form of [Co(NH₃)₅(NO₂)]Cl₂.
• NO₂⁻ through O: nitrito-O (O से NO₂⁻: नाइट्रिटो-O) — M–ONO. Gives the red form of [Co(NH₃)₅(NO₂)]Cl₂ — linkage isomerism.
• SCN⁻: through S or through N (SCN⁻: S से या N से) — M–SCN = thiocyanato-S; M–NCS = thiocyanato-N (isothiocyanato in older books).

Original diagram drawn by Simple Learning Hub, based on NCERT §5.2(c). Report a mistake