Isomerism Flashcards
What geometries are possible for a molecule with co-ordination number 4?
Square planar
Tetrahedral
What angle is in square planar?
90 degrees
What angle is in tetrahedral?
109 degrees
What geometries are possible for a molecule with a co-ordination number 5?
Trigonal bipyramidal
Square based pyramidal
What is the angle in SBP?
90 degrees
What are the angles in TBP?
120 and 90 degrees
What geometries are possible for a molecule with a co-ordination number 6?
Octahedral
Prismatic
What is the angle in octahedral?
90 degrees
What are the angles in prismatic?
85 and 95 degrees
What are the two types of ligand?
Neutral
Anionic
What are some examples of neutral ligands?
H2O
NH3
PPh3
What is used for bonding in neutral ligands?
Lone pair
What are some examples of anionic ligands?
F- Cl- O 2- Me- H-
What is used for bonding in anionic ligands?
Negative charge
What is an ambidentate ligand?
Ligands that can bind using different atoms and can choose which one they want to bind to
What is an example of a ambidentante ligand?
Nitrite (-NO2)
Can bind through either the nitrogen or the oxygen
What is a chelate ring?
A ring formed using a bidentante ligand
What is a bidentate ligand?
One ligand that has two binding sites and binds at the same time
Why is it better to use one bidentante ligand compared to 2 monodentate ligands?
The chelate rings formed are very stable
What are the two types of square planar?
Cis
Trans
What is a cis square planar molecule?
The X groups are adjacent
What is a trans square planar molecule?
The X groups are opposite to each other
How many isomers of the tetrahedral geometries are there?
1
How many isomers for [MX2L4] can you form?
2 - one cis and one trans
What type of isomers can you form with [MX3L3]?
Mer and Fac
What is a meridonal isomer for octahedral?
The three ligands and the metal are in the same plane
What is a facial isomer for octahedral?
Three identical ligands occupy one face with the metal not in plane
What are enantiomers?
Optical isomers which are non-superimposible mirror images
Are octahedral molecules with 3 bidentate ligands superimposible?
No
Are prismatic molecules with 3 bidentate ligands superimposible?
Yes
Why can’t bidentate ligands occupy trans positions?
They cant reach around only occupy 90degree cis arrangements
What is ionisation isomerism?
When either halide can coordinate
eg. [PtCl(NH3)3]+I- or [PtI(NH3)3]+Cl-
What is linkage isomerism?
Type of isomerism which occurs due to ambidentate ligands and depends on which donor atom is co-ordinated
