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If the complex ion is an anion, the name of the metal ends with the suffix – ate.įor example: 3‒ Trioxalatochromate (III) ion.ĬBSE Class 12th Chemistry Notes: Surface Chemistry

2+ Dichloridobis (1, 2 – ethanediamine) platinum (IV) ion. then we use bis – (for two), tris (for three) as prefix. If the ligands itself include di, tri etc. Then the name the metal atom is written followed by its oxidation state in Roman numerals.įor example: SO 4 Tetra ammine copper (II) sulphate In case of polydentate ligands, ligands are named alphabetically using a prefix di, tri, tetra, penta etc, to indicate the number of ligands of that type present. The ligands are then listed in alphabetical order. The oxidation number is indicated by Roman numerals.Ĭations are always named before the anions. The oxidation number of the central atom is defined as the charge left on a given atom when all other atom in a complex are removed as ions. For example: In K 4, Fe has coordination number 6. It is defined as the number of coordinate bonds formed by central metal atom, with the ligands. Such cyclic metal complex is called chelate and the ligands which gives chelates are called chelating ligands, and the process is known as chelation.ĬBSE Class 12th Chemistry Notes: General Principles and Processes of Isolation of Elementsĭenticity is defined as the number of coordinating atoms present per ligand. Polydentate: Ligand containing several donor sites are called polydentate.įor example: N(CH 2CH 2NH 2) 3 (Nitrilotriethylamine, a tetradentate ligand )ĮDTA (Ethylene Diamine tetraetato ion): It is a hexadentate ligand.Īmbidentate ligand: This is the ligand which can ligate through two different atoms present in it.įor examples: NO 2− ion can coordinate either through nitrogen or through oxygen to a central metal atom/ion.ĭi- and ploydentqte ligands results in the formation of cyclic structure around the central metal atom. ĭiddentate:It is the ligand which has two coordinating sites available.įor example: H 2NCH 2CH 2NH 2 (ethane-1, 2-diamine) and C 2O 4 2‒ (oxalate). Monodentate: It is the ligand which has only one coordinating atom.įor example: X ‒ (halido), NH 3 (ammine), H 2O (aqua), CN ‒ (Cynaido). On the basis of number of coordinating atoms present ligands may be classified as follows: Neutral ligands: NH 3 (ammine), H 2O (aqua), CO (carbonyl), etc. On the basis of charge present, ligands may be categorized into the following three groups:Īnionic ligands: CN ‒ (cyanide), NO 2 ‒ (nitrito-N), NO 3 ‒ (nitrito), X ‒ (halido), etc.Ĭationic ligands: NO 2 + (nitrosonium), NO + (nitronium), N 2F 5 + (Hydrazenium), etc.

NCERT Exemplar Questions & Solutions: CBSE Class 12 Chemistry – All Chapters Ligands are Lewis bases which donates electron pair and forms coordinate bonds with the metal atom.Ī ligand may be neutral, positively or negatively charged. The atoms or groups which are attached directly to central atoms are called ligands.

The atom or ion to which a fixed number of ions or groups are bound in a definite geometrical arrangement around it, is called the central atom or ion.įor example: In K 4, Fe 2 is the central metal ion. They are stable in solid state but dissociate into constituent ions when dissolved in water.įor example: FeSO 4. When two salts in stoichiometric ratio are crystallised together from their saturated solution they are called double salts. O Structure of some important metal carbonyls O Crystal field splitting in tetrahedral complexes