Date: 05/01/2022

Faculty Name : Mr. Mahesh K. Mahale

LMS user name : mahale.mahesh@mvpsvktcollege.ac.in

Course: S.Y.B.Sc. Chemistry

Year : Second

Semester: 3^rd

Subject: Inorganic Chemistry

Unit : 2^nd

Chapter name: Introduction to coordinator Compounds

Session name:

Asynchronous lecture no : 4

Intended date of publishing: 31/12/2021

Nomenclature of Inorganic complexes

• Anionic Complexes
• Cationic complexes
• Non-ionic Complexes
• Name of ligands
• Order of listing ligands

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2

Nomenclature of Inorganic complexes

• Naming of prefixes
• Oxidation states
• Point of attachments
• Abbreviations
• Bridging group

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3

1) Naming of prefixes

• Sometimes a single molecule of the ligand contains the word di or tri or tetra in its name.
• If two or more molecules of such ligands are present in the complex, then to avoid the repetition of words ‘di’ ‘tri’ etc., the prefixes in Greek language ‘bis’, ‘tris’, ‘tetrakis’ etc. are used before the name of ligand.

For example;

• [Co(en)₂Cl₂]CI →

Dichlorobis(ethylenediamine)cobalt (III) chloride.

2) Oxidation state

• The oxidation state of the central atom is shown by Roman numerals as I, II, III or 0 in parantheses () after the name of the metal without a space between the two.
• For a negative oxidation state a minus sign is used before the Roman figure and 0 is used for zero oxidation state.
• Ex. K₄[Ni(CN)₄] Potassium tetracyanonickelate (0)

Point of attachment:

• If a ambidentate ligand has within itself more than one atom which can donate the electron pair it becomes necessary to show which atom is acting as donor, then the symbol of the donor atom is written after the name of the ligand with separation by a hyphen.

EXAMPLE

• (NH₄)₃[Cr(NCS)₆]

Ammonium hexathiocyanato-N-chromate (III) or Ammonium isothiocyanatochromate (III)

• (NH4)2[Pt(SCN)6] is written as,

Ammonium hexathiocyanato-S-platinate (IV)

• In case of nitrite ions, it is -NO₂^- Nitro, -ONO^- nitrito

Bridging groups:

• Ligands that bridge two metal atoms in a polynuclear complex are preceded by the Greek letter u.
• It is repeated before the name of each different kind of bridging group. The resulting complex is called a ‘bridged complex’.

For Example:

Nomenclature of Inorganic complexes

• Naming of prefixes
• Oxidation states
• Point of attachments
• Abbreviations
• Bridging group

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• Nomenclature of coordination Compounds (IUPAC)

1) Isomerism in coordination complexes

2) werner’s work and theory of coordination compounds

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