Complex ions Flashcards
What is a complex
A complex is a central metal atom or ion surrounded by co-ordinately bonded ligands
What is a dative covalent bond?
A covalent bond in which both electrons in the shared pair come from the same atom.
What is a ligand?
A ligand is an atom, ion or molecule that donates a pair of electrons to a central transition metal ion to form a dative covalent bond.
What is the co-ordination number?
The number of dative covalent bonds
basically just the total number of bonds
what colour is [CuCl4]2-
yellow
what colour is [CoCl4]2-
Blue
6 coordinate bonds vs 4 coordinate bonds:
6 coordinate bonds can normally be formed if ligands are small, however if ligands are large, then normally 4 coordinate bonds are formed
- 6 co-ordinate bonds shape= octahedral
- 4 co-ordinate bonds shape= tetrahedral OR square planar.
2 coordinate bonds
Form a linear shape
e.g [Ag(NH3)2]+
^ this is actually tollens reagent
How do you work out oxidation state of metals? (equations)
Ox state(metal)=total ox - sum of ox states of ligands
what is a monodentate ligand
A ligand that can only form one co-ordinate bond
What is a lignad that can form more than one coordinate bond called?
Multidentate
a ligand that can form 2 co-ordinate bonds is called?
Bidentate
what is “haem”
4 nitrogen atoms coordinated around Fe2+, to form a circle.
This is where FOUR out of SIX of the coordinate bonds come from for haemoglobin
Where do the other 2 co-ordinate bonds come from in haemoglobin
From GLOBIN (protein)
AND an oxygen molecule or water molecule.
How can carbon monoxide stop oxyhaemoglobin from forming?
Haemoglobin swaps its water ligand for a carbon monoxide ligand, forming carboxyhaemoglobin
- This means that haemoglobin can no longer transport oxygen around the body anymore.
- this can cause: headaches, dizziness, unconsciousness and even death, if left untreated.
