coordination compouds

Definition: What is the simple rule to distinguish a Double Salt from a Coordination Compound?

In a Double Salt, the complex loses its identity in solution. In a Coordination Compound, it retains its identity in solution.

Example: Give three examples of Double Salts with their chemical formulas.

1. Mohr's Salt: FeSO4(NH4)2SO4.6H2O. 2. Carnallite: KCl.MgCl2.6H2O. 3. Potash Alum: K2SO4.Al2(SO4)3.24H2O.

Ligands: What are ligands?

They are Lewis bases that can donate at least one lone pair of electrons to the central metal atom.

Monodentate: What is a monodentate (unidentate) ligand?

It is a ligand with only one donor atom.

Monodentate: Give examples of monodentate ligands.

H2O, CN-, Br-, Cl-, OH-, NH3

Bidentate: What is a bidentate ligand?

It is a ligand that consists of two donor atoms.

Bidentate: Give examples of bidentate ligands.

en, ox, gly, acac, dmg, dipy (bipy), phen

Bidentate: What is the name, abbreviation, and structure of the "en" ligand?

Name: Ethylenediamine. Abbreviation: en. Structure: H2N-CH2-CH2-NH2 (two Nitrogen donor atoms).

Bidentate: What is the name, abbreviation, and structure of the "ox" ligand?

Name: Oxalato. Abbreviation: ox. Structure: A 2-carbon chain with a carboxylate group (-COO-) at both ends: (-OOC-COO-).

Bidentate: What is the name, abbreviation, and structure of the "gly" ligand?

Name: Glycinato. Abbreviation: gly. Structure: H2N-CH2-COO- (one Nitrogen and one Oxygen donor atom).

Bidentate: What is the name, abbreviation, and structure of the "acac" ligand?

Name: Acetylacetonato. Abbreviation: acac. Structure: CH3-C(O-)=CH-C(O-)-CH3 (two Oxygen donor atoms).

Bidentate: What is the name, abbreviation, and structure of the "dmg" ligand?

Name: Dimethylglyoximato. Abbreviation: dmg. Structure: CH3-C(=N-OH)-C(=N-OH)-CH3 (two Nitrogen donor atoms).

Bidentate: What is the name, abbreviation, and structure of the "dipy" or "bipy" ligand?

Name: 2,2'-dipyridyl or Bipyridyl. Abbreviation: dipy or bipy. Structure: Two pyridine rings connected by a single bond at the 2 and 2' positions (two Nitrogen donor atoms).

Bidentate: What is the name, abbreviation, and structure of the "phen" ligand?

Name: 1,10-phenanthroline. Abbreviation: phen. Structure: Three fused rings where two Nitrogen atoms are positioned to bind to a metal.

Polydentate: What is a polydentate ligand?

A ligand that contains more than two donor atoms.

Tridentate: What is a tridentate ligand? Give examples.

A ligand with three donor atoms. Examples: dien (diethylenetriamine) or terpy (terpyridine).

Tridentate: What is the name, abbreviation, and structure of the "dien" ligand?

Name: Diethylenetriamine. Abbreviation: dien. Structure: H2N-CH2-CH2-NH-CH2-CH2-NH2 (three Nitrogen donor atoms).

Tridentate: What is the name, abbreviation, and structure of the "terpy" ligand?

Name: Terpyridine. Abbreviation: terpy. Structure: Three pyridine rings connected in a line (three Nitrogen donor atoms).

Tetradentate: What is the name, abbreviation, and structure of the "trien" ligand?

Name: Triethylenetetramine. Abbreviation: trien. Structure: H2N-CH2-CH2-NH-CH2-CH2-NH-CH2-CH2-NH2 (four Nitrogen donor atoms).

Pentadentate: What is the name, abbreviation, and structure of the EDTA 3- ion?

Name: Ethylenediaminetriacetate ion. Abbreviation: [EDTA]3-. Structure: Contains five donor atoms (2 Nitrogen, 3 Oxygen).

Hexadentate: What is the name, abbreviation, and structure of the EDTA 4- ion?

Name: Ethylenediaminetetraacetate ion. Abbreviation: [EDTA]4-. Structure: Contains six donor atoms (2 Nitrogen, 4 Oxygen).

Ambidentate: What is an ambidentate ligand?

A monodentate ligand that contains two different donor atoms, but can only coordinate through one of them at a time.

Ambidentate: Give examples of ambidentate ligands.

NO2-, SCN-, CN-, S2O3 2-

Chelating Ligands: What is a chelating ligand?

A bidentate or polydentate ligand that can form a ring-like or cyclic structure with the central metal atom.

Chelating Ligands: What are three important points about chelation?

1. The stability of the complex increases. 2. The complexes are called chelates. 3. The process is called chelation.

Chelating Ligands: Give examples of chelating ligands.

ox, gly, dien, etc.

Flexidentate Ligands: What are flexidentate ligands? Give examples.

Ligands that can show different denticities depending on the situation. Examples: SO4 2-, CO3 2-, EDTA.

Flexidentate Ligands: What denticities can SO4 2- show?

It can be monodentate or bidentate.

Flexidentate Ligands: What denticities can CO3 2- show?

It can be monodentate or bidentate.

Flexidentate Ligands: What denticities can EDTA show?

It can show tetradentate, pentadentate, or hexadentate.

Homoleptic vs Heteroleptic: What is a homoleptic complex?

A complex in which all the ligands attached to the central metal atom are the same.

Homoleptic vs Heteroleptic: What is a heteroleptic complex?

A complex in which the ligands attached to the central metal atom are different.

Coordination Number: What is the coordination number?

The total number of ligand donor atoms to which the central metal is directly bonded.

Counter Ion: What is a counter ion?

The ion that balances the charge of the coordination sphere.

Metal Naming (Anions): If the metal in an anionic complex is Cobalt (Co), what is its name?

Cobaltate

Metal Naming (Anions): If the metal in an anionic complex is Zinc (Zn), what is its name?

Zincate

Metal Naming (Anions): If the metal in an anionic complex is Chromium (Cr), what is its name?

Chromate

Metal Naming (Anions): If the metal in an anionic complex is Iron (Fe), what is its name?

Ferrate

Metal Naming (Anions): If the metal in an anionic complex is Silver (Ag), what is its name?

Argentate

Metal Naming (Anions): If the metal in an anionic complex is Gold (Au), what is its name?

Aurrate

What is the name and charge of the ligand: H2O?

Name: aqua. Charge: 0

What is the name and charge of the ligand: NH3?

Name: ammine. Charge: 0

What is the name and charge of the ligand: CO?

Name: carbonyl. Charge: 0

What is the name and charge of the ligand: NO?

Name: nitrosyl. Charge: 0

What is the name and charge of the ligand: C5H5N (py)?

Name: pyridine. Charge: 0

What is the name and charge of the ligand: (C6H5)3P (PPh3)?

Name: triphenylphosphine. Charge: 0

What is the name and charge of the ligand: en?

Name: ethylenediamine. Charge: 0

What is the name and charge of the ligand: dien?

Name: diethylenetriamine. Charge: 0

What is the name and charge of the ligand: trien?

Name: triethylenetetraamine. Charge: 0

What is the name and charge of the ligand: dipy?

Name: dipyridyl. Charge: 0

What is the name and charge of the ligand: phen?

Name: phenanthroline. Charge: 0

What is the name and charge of the ligand: CS?

Name: thiocarbonyl. Charge: 0

What is the name and charge of the ligand: NH2CONH2?

Name: urea. Charge: 0

What is the name and charge of the ligand: NH2-CS-NH2?

Name: thiourea. Charge: 0

What is the name of the ligand CN? What is its charge?

Name: cyanido. Charge: -1

What is the name of the ligand SCN? What is its charge?

Name: thiocyanato-S. Charge: -1

What is the name of the ligand NCS? What is its charge?

Name: thiocyanato-N. Charge: -1

What is the name of the ligand H? What is its charge?

Name: hydrido. Charge: -1

What is the name of the ligand HS? What is its charge?

Name: mercapto. Charge: -1

What is the name of the ligand OH? What is its charge?

Name: hydroxido. Charge: -1

What is the name of the ligand NH2? What is its charge?

Name: amido. Charge: -1

What is the name of the ligand CH3COO? What is its charge?

Name: acetato. Charge: -1

What is the name of the ligand gly? What is its charge?

Name: glycinato. Charge: -1

What is the name of the ligand acac? What is its charge?

Name: acetylacetonato. Charge: -1

What is the name of the ligand dmg? What is its charge?

Name: dimethylglyoximato. Charge: -1

What is the name of the ligand NO2 (bonded through N)? What is its charge?

Name: nitrito-N. Charge: -1

What is the name of the ligand ONO (bonded through O)? What is its charge?

Name: nitrito-O. Charge: -1

What is the name of the ligand NO3? What is its charge?

Name: nitrato. Charge: -1

What is the name of the ligand N3? What is its charge?

Name: azido. Charge: -1

What is the name of the ligand F? What is its charge?

Name: fluorido. Charge: -1

What is the name of the ligand Cl? What is its charge?

Name: chlorido. Charge: -1

What is the name of the ligand Br? What is its charge?

Name: bromido. Charge: -1

What is the name of the ligand I? What is its charge?

Name: iodido. Charge: -1

What is the name of the ligand O? What is its charge?

Name: oxo. Charge: -2

What is the name of the ligand O2? What is its charge?

Name: peroxo. Charge: -2

What is the name of the ligand S? What is its charge?

Name: thio (or sulphido). Charge: -2

What is the name of the ligand SO3? What is its charge?

Name: sulphito. Charge: -2

What is the name of the ligand SO4? What is its charge?

Name: sulphato. Charge: -2

What is the name of the ligand S2O3? What is its charge?

Name: thiosulphato. Charge: -2

What is the name of the ligand CO3? What is its charge?

Name: carbonato. Charge: -2

What is the name of the ligand C2O4? What is its charge?

Name: oxalato. Charge: -2

What is the name of the ligand NH? What is its charge?

Name: imido. Charge: -2

What is the name of the ligand N? What is its charge?

Name: nitrido. Charge: -3

What is the name of the ligand EDTA 3? What is its charge?

Name: ethylenediaminetriacetato. Charge: -3

What is the name of the ligand EDTA 4? What is its charge?

Name: ethylenediaminetetraacetato. Charge: -4

What is the name of the ligand NO? What is its charge?

Name: nitrosonium. Charge: +1

What is the name of the ligand NO2 (as a positive ion)? What is its charge?

Name: nitronium. Charge: +1

What is the name of the ligand NH2-NH3? What is its charge?

Name: hydrazinium. Charge: +1

charge of potassium K

+1

Charge of sodium Na

+1

Charge of chlorine Cl

charge = -1

Possible charges for platinum

+2 and +4

Possible charges for palladium

+2 and +4

what to do if name already contains a prefix?

use bis, tris, tetrakis, pentakis for numbering instead of bi, tri, tetra, penta

IUPAC name of brown ring complex

PentaaquanitrosoniumIron (I) sulphate

What is a bridging ligand?

A ligand that simultaneously binds to two or more central metal atoms (forming a bridge between them).

What is the symbol used for a bridging ligand in a chemical formula?

The Greek letter mu (μ) is used as a prefix before the ligand name.

In the formula [(NH3)4Co(OH)2Co(NH3)4]Cl4, what are the two OH groups acting as?

They are bridging ligands (μ-OH).

When naming coordination compounds, when do you use "bis" instead of "di"?

Use "bis" (or tris, tetrakis) when the name of the ligand itself already contains a numerical prefix (e.g., tetraammine) or is a multi-word complex enclosed in brackets.