metal complex's Flashcards
general rule for metal complex shapes
for 4 ligands, if the metal is platinum of palladium then its square planar. otherwise its tetrahedral
copper complex colours/states
6 (H2O) ligands: pale blue solution
4 (H2O), 2(OH) ligands: blue precipitate
2 (H2O), 4(NH4) ligands: dark blue solution
iron 2+ complex colours/solutions
6 (H2O) ligands: pale green solution
4 (H2O), 2(OH) ligands: green precipitate (slowly turns brown due to oxidation to Fe3+)
iron 3+ complex colours/solutions
6 (H2O) ligands: yellow solution
3 (H2O), 3 (OH) ligands: orange precipitate
manganese complex colours/states
6 (H2O) ligands: pale pink solutions
4 (H2O), 2 (OH) ligands: pink precipitate
chromium complex colours/states
6 (H2O) ligands: green solution
3 (H2O), 3(OH) ligands: grey-green precipitate
6 (OH) ligands: dark green solution
6 (NH3) ligands: purple solution
which metal complexes have further reactions with excess OH- ions or NH3
Cu with NH3 to form [Cu(NH3)4 (H2O)2]^2+
Cr with OH- to form [Cr(OH)6]^3-
Cr with NH3 to form [Cr(NH3)6]^3+
why are CN- or CO poisonous
they bond to haemoglobin in a ligand substitution reaction instead of oxygen, preventing oxygen transfer
how does cisplatin kill cancer cells
prevents DNA replication by a ligand substitution reaction. two coordinate bonds are formed between the platinum and nitrogen atoms on 2 adjacent bases. the nitrogen replaces the 2 chlorine ligands. it also targets healthy cells
what affects metal complex colours
identity of the metal,
oxidation state,
ligands type,
coordination number.
why do metal complex’s have colours
the difference in energy of the split d orbitals corresponds to the energy of light absorbed. electrons are excited to higher energy levels. the colour of the complex corresponds to the frequencies of light not absorbed
what is meant by the d-orbitals in metal complex’s being ‘split’
the d-orbitals have different energies because each orbital interacts differently with the bonding ligands.
