Transition Metals Flashcards
What is a transition metal?
An element with partially filled d-orbital shell
What are base metals?
Metals that oxidise or corrode easily
What are 3 examples of base metals?
- Fe
- Cu
- Zn
What are noble metals?
Metals that resist oxidisation or corrosion
What are 2 examples of noble metals?
- Au
- Ag
What is the general rule for filling of metal atom orbitals?
4s fills before 3d
What are 2 exceptions to 4s filling before 3d, and why?
- Cr will have a half filled 4s orbital to give each 3d orbital 1 electron
- Cu will have a half filled 4s orbital to give fully fill each 3d orbital
For metals atoms/ions in coordination complexes, where are electrons first removed from?
The 4s orbital
How can you easily work out the number of electrons in the d-orbital of a metal ion?
Group number - oxidation state = number of d electrons
What is coordination number?
The number of donor atoms around the metal species
Does coordination number include counter ions?
No
What are ligands?
Molecules which donate a lone pair to the metal to form a dative bond (i.e ligands donate electrons)
What charge are ligands?
Ligands can be neutral, or negatively charged
Do all ligands correspond to the same bond strength with the metal?
No. Different ligands correspond to different bond strengths: e.g. CN- forms a much stronger bond that Cl-
What are monodentate ligands?
A lone pair donated from one donor atom
What are some examples of monodentate ligands?
- Acetato
- Hydroxo
- Pyridine
- Carbonyl
What are bidentate ligands?
Ligands which can donate lone pairs from 2 donor atom
What are some examples of bidentate ligands?
- En
- Bipy
- Ox2-
- Acac-
What is the chelate effect?
Complexes of multi dentate ligands have a greater stability that monodentate ligands.
The result is that multidentate ligands readily display monodentate
What is coordinative/ionisation isomerism?
Isomers which differ in which of the ligands are bonded to the metal, and/or which act as counterions
What is linkage isomerism?
Isomers which differ by which atom on the ligand is used to bond to the metal (i.e which acts as the donor atom).
Only occurs with ambidentate ligands