15:Transition Metals Flashcards
What is a transition metal?
d-block elements that form one or more stable ions with incompletely filled d-orbitals.
Why do transition metals have varying oxidation numbers?
There is no sudden jump in ionisation energy. This means the energy required to form the bond is less than the energy produced when the bond forms.
What is a ligand?
An ion or molecule that donates a lone pair to form a dative covalent bond.
What is a complex ion?
A central metal ion surrounded by ligands.
Why do complex ions form coloured solutions?
When a ligand forms a dative covalent bond there is repulsion between d-orbitals. This causes them to move to higher energy levels. Certain wave lengths of light are absorbed and the rest is reflected which causes the colour.
What does the colour of a metal ion depend on?
Oxidation state of the metal. The ligand. The coordination number.
What is a coordination number?
The number of bonds between the metal ion & the ligands.
What is a Monodentate ligand?
They only form one dative covalent bond with the metal ion. (only one biting point)
What are some examples of mono dentate ligands?
H2O, OH- & NH3
What mono dentate ligands form octahedral shape?
H2O, OH- & NH3.
What mono dentate ligands for tetrahedral complexes?
Cl-
What is cis-plain?
Square planar complex where the two chlorine are on the same side. It is used to treat cancer.
How is cis-plain used to treat cancer?
It binds to two guanines next to each other which stops DNA replication. Ligand exchange between Cl- & H2O.
Why can’t trans-Platin be used to treat cancer?
The geometry is wrong.
What is a bidentate ligand?
Forms two dative covalent bonds with the metal ion.
