Inorganic Chemistry - Semester 2 Flashcards
What is the coordination number?
The number of donor atoms around a transitional metal.
What are the four types of constitutional isomerism?
Linkage isomerism.
Coordination isomerism.
Ionisation isomerism.
Solvate isomerism.
What is linkage isomerism?
Where an ambidentate ligand is connected by a different atom.
For example NO₂ and ONO.
What is coordination isomerism?
Where there is an anionic and cationic transition metal complex connected, coordination isomerism is the changing of the ligands from the cation to the anion.
What is ionisation isomerism?
Where a ligand in the inner sphere swaps with a ligand in the outer sphere.
What is solvate isomerism?
A special type of ionisation isomerism where water is swapped between the inner and outer sphere.
What is stereoisomerism?
The are the atom-atom connectivities are identical but the individual atoms are arranged differently in space.
What are the two types of stereoisomerism?
Geometrical isomerism.
Optical isomerism.
What is geometrical isomerism?
In square planar structures, it is in the form of cis-trans isomerism.
In octahedral complexes it can happen as cis-trans isomerism or mer-fac isomerism.
What is mer-fac isomerism?
Where there are equal numbers of two types of ligands in an octahedral complex, the three ligands can form a meridonal arrangement (in a single plane) or a facial arrangement (when connected form a face of the octahedron).
What is a hard metal?
A metal with a high charge density. They favour forming bonds to ligands which are small and electronegative.
The bonding between the hard metal and the hard ligand has a high degree of ionic character.
What is a soft metal?
A metal with a lower charge density and is more polarisable. They form bonds with ligands that are large and polarisable.
The bonding between the soft metal and the soft ligand has a high degree of covalent character.
Which sub-shells are filled first for neutral gaseous transition metals?
The 4s is filled before the 3d.
Which sub-shells are filled first when a transition metal atom or ion is bound to ligands?
The 3d level fills before the 4s.
What happens to the energy of 3d electrons when a ligand binds to it?
The energy increases.
What is the 3d splitting pattern in an octahedral complex?
The dxy, dxz and the dyz orbitals decrease in energy and form the t2g orbitals.
The dz2 and dx²-y² orbitals increase in energy and form the eg orbitals.
What are the values of ΔO for an octahedral splitting pattern?
The t2g orbitals have a value of -0.4ΔO.
The eg orbitals have a value of +0.6ΔO.
What is a high spin configuration?
A configuration where the number of unpaired spins is maximised.
What is a low spin configuration?
A configuration where the number of unpaired spins is minimised.
What is the effect of ΔO on the high/low spin configuration?
A large ΔO outweighs the pairing energy and so the complex will be low spin.
A small ΔO leads to high spin complexes.
How does the metal influence ΔO?
The greater the oxidation state, the greater the value of ΔO.
The further down the periodic table, the greater the value of ΔO.
How does the ligand influence ΔO?
A “strong field” ligand (CN⁻, CO, PR₃, bipy) will cause a large ΔO.
A “weak field” ligand (water, hydroxide ions and halide ions) will cause a small ΔO.
What is the splitting pattern for tetrahedral complexes?
The dz² and dx²-y² orbitals decrease in energy and form the e orbitals.
The dxy, dxz, dyz orbitals increase in energy and form the t₂ orbitals.
What are the values for Δt?
The t₂ orbitals have a value of +0.4Δt.
The e orbitals have a value of -0.6Δt.
How does Δt compare to Δo?
Δt is less than Δo.
Δt has a value of around 4/9 of Δo.
What configurations does tetrahedral splitting form?
Only high spin complexes.
This is because the value of Δt are never large enough to offset the pairing energy.