FeCl3 + K4[Fe(CN)6] Fe4[Fe(CN)6]3 (Prussian blue)
Coordination Compounds
Statement I is true but statement II is false. Only oxygen atom forms a Co-ordinate bond with Cu+2 in CuSO4.5H2O
[Ni(CN)4]2– : d8 configuration, SFL, sq. planar splitting (dsp2), diamagnetic.
[Ni(CO)4] : d10 config (after excitation), SFL, tetrahedral splitting (sp3), diamagnetic.
[NiCl4]2– : d8 config, WFL, tetrahedral splitting (sp3), paramagnetic(2 unpaired e–).
Cis-platin is [Pt(NH
)
Cl
]; cis platin and other complexes of pt are used to inhibit the growth of tumours.
Crystal field splitting
for octahedral complexes depends on oxidation state of the metal as well as to which transition series the metal belongs.
For the same oxidation state, the crystal field splitting
increases as we move from
and
belong to
series,
belongs to
series and
belongs to
series. Therefore crystal field splitting
is highest for
.
Stronger is ligand attached to metal ion, greater will be the splitting between
and (hence greater will be
Greater will be absorption of energy. Hence correct order
is diamagnetic
configuration No unpaired electrons.
and
are paramagnetic in nature
Ligands like : CO, are sigma donor and -acceptor and they make stronger bond with lower oxidation state metal ion, in this case back bonding is more effective
According to John teller any nonlinear molecular system in a degenerate electronic state will be unstable and will undergo some kind of distortion which will lower its symmetry and energy and split the degenerate state.
In case of octahedral
configuration, the last electron may occupy either
or
orbitals of
set. If it occupies
orbital most of the electron density will be concentrated between the metal and the two ligands on the
axis.
Thus there will be greater electrostatic repulsion associated with these ligands than with the other four on xy plane.
The Jahn Teller effect is mostly observed in octahedral environments.
The considerable distortions are usually observed in high spin
, low spin
and
configuration.