1. General Properties 2.5. Shapes of Complex Ions
• Isomer – compound with same mole
Transition Metal—Forms at least 1 stable ion with a part full “d” shell • Differences in shape occur due to varying ligand
different structural formula
of electrons sizes – a larger ligand means that less can fit in
Geometrical:
Scandium and Zinc are not transition metals the space around the central metal ion
• Occurs in octahedral and square planar
Properties: good heat and electricity conductors e.g. Cl ligand is larger than NH3 ligand
Example is platin (square pl
hard, strong, shiny
There are a few trans-platin
high mpt and bpt
examples of square Optical:
low chemical reactivity
planar: • Occurs when 2 or more bidentate ligands
variable oxidation states
[Ni(CN)4]2- present in complex
catalytic action
[Pt(Cl)4]2- • They are chiral
coloured complexes
[Pt(Cl)2(NH3)2] PLATIN • Distinguished by effect on plan polarized l
formation of complexes
2.1. Aqua Ions
1.1. Electron Configuration Dissolving a salt of a T.M in water, the positively 2.4. Haemoglobin
➢ 4s fills before 3d, 4s also empties before 3d charged metal ion is surrounded by polar water • Carries oxygen around body
❖ Chromium has config of [Ar] 4s1 3d5 molecules acting as ligands • Molecule has an Fe2+ ion with coordination number of 6 (octahedral)
❖ Copper has config of [Ar] 4s1 3d10 They replace the salt and form an aqua ion • Complex ion called haem
➢ It’s believed that a half full “d” orbital level makes the atom more • Globin is the complex protein
stable
Inorganic Chemistry: Transporting O2:
Transition Metals • Oxygen substitutes the water ligands forming oxyhaemoglobin
2. Complex Ion Formation and their Shapes • Oxygen then given up to where it’s needed
All T.M ions can form coordinate bonds by accepting electron pairs from other • Water replaces oxygen again and goes back to lungs
ions/molecules
Ligand—particle with lone pair that bonds to metals via coordinate bond Bonding:
Complex—metal ion with coordinately bonded ligands • Fe2+ to O2 bond is weak, so Oxygen can be given off easily
Coordination Number—no. of coordinate bonds from ligands to non-metal • CO is a better ligand and stronger bond, which prevents oxygen transfer
Lewis Base—lone pair doner
Lewis Acid—lone pair acceptor
2.3. Chelate Effect
Chelation – process by which a multidentate liga
Ligand examples include: H2O, NH3, Cl, CN, EDTA and they all • H2O, NH3 and Cl are monodentate ligands, the H2O and NH3 monodentate ligands in forming a co
vary in their coordination number ligands are similar in size and uncharged, so an exchange of transition metal ion
these 2 will have no effect on coordination number. • When chelation occurs, there are more moles of p
6 bonds = octahedral • But the Cl ligand is larger so will cause a decrease in reactants used, this causes an increase in entropy
4 bonds = tetrahedral or square planar coordination number – more shielding than oxygen, higher to the right. More molecules = increases entropy
2 bonds = linear mass . Entropy - measure of disorder within a system
• NH2CH2CH2NH2 (each N has a lone pair) [shown above] and
Monodentate Ligands—form 1 coordinate bonds with a T.M C2O4 are bidentate ligands • Complex ions with larger stability constants are mo
Bidentate Ligands—form 2 coordinate bonds • EDTA is polydentate (forms 6 coordinate bonds, lone pairs on smaller ones
Polydentate Ligands—form more than 2 coordinate bonds 4 oxygen atoms and 2 nitrogen atoms • EDTA is a chelating agent and used to prevent pois
Complex ions with polydentate ligands are
called chelates. Chelates are used to
remove “d” block metal ions from solution