3.2.5.3 Shapes of Complex Ions Flashcards
What is the shape of an ion with a co-ordinate number of six?
Octahedral
e.g. [Co(NH3)6]3+
What is the shape of the ion with a co-ordinate number of four?
Tetrahedral, e.g. [CoCl4]2-
Or some ions are square planar (flat rhombus shape)
e.g. [NiCN4]2-
What does an octahedral shape look like?
Six points with eight faces
What is the difference in size between Cl-, NH3 and H2O as ligands?
Cl- is larger
NH3 and H2O are similar in size
What are the effects of chlorine being a bigger ligand?
Fewer ligands can get around the central atom
What is Tollens reagent?
[Ag(NH3)2]+
Aldehydes reduce it to Ag while ketones do not
A silver mirror is formed
It is a linear molecule: H3N —> N
What are the four main shapes of transition metal complexes?
Linear: — M —
Tetrahedral: two straight, one dotted, one wedge
Square planar: two dotted, two wedges
Octahedral: two straight, two dotted, two wedges
What is the type of isomerism in transition metal complexes?
Geometric isomers (EZ) Optical isomers
Why do transition metal complexes experience geometrical isomerism?
The monodentate ligands differ in their position
This occurs in octahedral and square planar complexes
One type of ligand is next to each other (Z) or on opposite sides (E)
Why do transition metal complexes experience optical isomerism?
When there are two or more bidentate ligands in a complex
You find the isomer by rotating one of the complexes around a vertical axis
They are chiral
What type of isomer is cisplatin?
Z form of geometrical isomerism
