Hey there! We receieved your request
Stay Tuned as we are going to contact you within 1 Hour
One of our academic counsellors will contact you within 1 working day.
Click to Chat
1800-5470-145
+91 7353221155
Use Coupon: CART20 and get 20% off on all online Study Material
Complete Your Registration (Step 2 of 2 )
Sit and relax as our customer representative will contact you within 1 business day
OTP to be sent to Change
Introduction to Naming of Co-ordination Compounds
In Coordination Compounds
Rule 1
Rule 2
Rule 3
Rule 4
Rule 5
Rule 6
Rule 7
Related Resources
Just like nomenclature of organic compounds, nomenclature is important in Coordination Chemistry also. Naming of coordination compounds is needed for providing an unambiguous method for representing and describing formulas and names of coordination compounds systematically. The nomenclature becomes even more important when dealing with the isomers of the same coordination compound.
The formulas and names which are used for coordination compounds are based on the rules of the International Union of Pure and Applied Chemistry (IUPAC).
Before we learn how to write name of any coordination compounds, lets firs learn how to write the formula of any coordination compound
The formula of a coordination compound is a tool which is used for providing basic information regarding the constitution of the coordination compound in a brief,convenient and meaningful manner.
Within the coordination entities the central atom/ion is listed first followed by the ligands
The ligands are then listed after the central metal atom/ion in alphabetical order.
The formula of coordination entity, is written in square brackets.
Ligand abbreviations are also writtenin parentheses.
There should be no space between the ligands and the metal within a coordination sphere.
The charge on the cation(s) is balanced by the charge of the anion(s).
Let’s have a look at these IUPAC rules for nomenclature of organic compounds one by one.
While naming a coordination compound, cation is always named before the anion irrespective of the fact that whether the complexion is cation or anion.
For example:
Na[Co(NH)4 (Cl)2] → Na is to be named first followed by [Co(NH)4 (Cl)2]
Sodium tetramminedichlorocoblatate(I)
[Co(NH)4 (Cl)2]SO4 → [Co(NH)4 (Cl)2] is to be named first followed by SO4
Tetraamminedichlorocobalt(0) sulphate.
If there are more than one type of ligands present in any coordination compound, the name of the ligands is to be done in alphabetic order followed by the name of central metal atom/ion.
Name of the anionic ligands, ends with ‘o”. For example, Chloride → Chlorideo, Nitrate → Nitrito
For neutral ligands, their common name are used as such e.g. H2NCH2CH2NH2 → ethylenediamine H2O → aqua, NH3 → ammine, CO → carbonyl N2 → dinitrogen| O2 → dioxygen.
Anionic ligands
Neutral ligands
Br–
Bromo
NH3
Ammine
F–
Fluoro
H2O
Aqua
O2–
Oxo
NO
Nitronyl
OH–
Hydroxo
CO
Carbonyl
CN–
Cyano
O2
Dioxygen
C2O42–
Oxalato
N2
Dinitrogen
CO32–
Carbonato
H2NH2C | H2NH2C
Ethylene diamine
CH3COO–
Aceto
If the names of the ligands already contains a numerical prefix , then the terms, bis, tris, tetrakis are used and the ligand to which they refer being placed in parentheses. For example, [NiCl2(PPh3)2] is named as dichloridobis(triphenylphosphine)nickel(II)
After naming the ligand in alphabetic order, name the central metal atom/ion is written.
If the complex ion is a cation, metal is named same as the element.
If the complex is an anion, the name of metal ends with the suffix -ate for Latin name.
English name
Latin name
Anion name
Copper
Cuprum
Cuprate
Gold
Aurum
Aurate
Iron
Ferrum
Ferrate
Lead
Plumbum
Plumbate
Silver
Argentum
Argentate
Tin
Stannum
Stannate
The oxidation state of the metal in the complex is given as a roman numeral in parentheses.
The neutral complex molecule is named similar to that of the complex cation.
These are some ligands which may be attached to the central metal atom/ion through different atoms. For example NO2, CN etc..
Thus M-NO2 → nitro
M-ONO → nitrito.
M-SCN → thiocyanato
M-NCS → isothiocyanato
Refer to the followinbg video for naming of coordination compounds
Solved Problem
llustration 1: IUPAC name of K2[Fe(NC)3Cl2(NH3)2]
Solutions: The positive part is named first followed by the negative part. In the negative part the names are written in alphabetical order followed by metal. So the name is Potassiumdiamminedichlorotricyano-N- ferrate (III)
Illustration 2: IUPAC name of [Co(NH3)4(NO2)2]Cl Solution: In the earlier two examples the negative part was the complex part while in this case the positive part is the complex. So it is named first with ligands in alphabetical order followed by metal (but not ending in –ate as the metal belong to the positive part of the complex). This is followed by the negative part. So the name is Tetraamminedinitrocobalt (III) chloride.
Illustration 3: Write IUPAC name of [Pt(Py)4][PtCl4].
Solution: Here both the positive and negative part has the same metal. Procedure is same earlier are the IUPAC name. Tetrapyridineplatinum(II) tetrachloroplatinate(II).
Illustration 4: Write the IUPAC name of [Fe(NH3)4O2C2O4]Cl
Solution: In this charge on the complex part is +1. The ligand oxalato has a charge of –2, so iron should be in +3 state meaning O2 to be neutral. Now had O2 been superoxo (O2–) or peroxo (O2– – ) the negative charge of the ligands should have been –3 and –4 respectively. In that case Iron has to be +4 and +5 which is not possible. So O2 will behave as a neutral ligand and IUPAC name is Tetraammineoxalatodioxygeniron (III) chloride.
Click here to get the introduction to coordination compounds.
You can also refer to the past year papers of IIT JEE
Click here to know about the best books of chemistry
You can also download the NCERT solutions for free.
To read more, Buy study materials of Coordination Compounds comprising study notes, revision notes, video lectures, previous year solved questions etc. Also browse for more study materials on Chemistry here.
Get your questions answered by the expert for free
You will get reply from our expert in sometime.
We will notify you when Our expert answers your question. To View your Question
Introduction to Co-Ordination Compounds Molecular...
Werner’s Theory of Coordinate Compounds...
Isomerism in Coordination Compounds Compounds that...
Examples on Naming of Co-ordination Compounds...
Solved Examples of Coordination Compounds Question...
Terminology The important terms used in the study...
Ligands It is an ion or molecule capable of...
Bonding in Co-ordination Compounds Transition...