Transcript Slide 1

Coordination complexes
[CoCl2(en)2]Cl
dichlorobis(en)cobalt(III) chloride
Cl
Cl
N
trans-
N
same
Co
N
Co
N
N
N
Cl
Cl
Cl
Cl
N
cis-
N
N
Co
N
Co
enantiomers
N
N
N
Cl
Cl
N
N
N
Coordination complexes
coordination number 4
Na[FeCl4]
[Pt(NH3)2Cl2]
sodium tetrachloroferrate(III)
diamminedichloroplatinum(II)
square planar
tetrahedral (rare)
Cl
Cl
cis
Fe
Pt
Cl
NH3
Cl
Cl
Cl
no geometric isomers
optical isomers
NH3
trans
H3N
Cl
Pt
Cl
NH3
no optical isomers
Bonding
localized electron model
octahedral
d 2sp3
square planar dsp2
tetrahedral
sp3
linear
sp
predicts shapes
does not predict colors
magnetic properties
Crystal Field Model
Crystal Field Model

dz2
dx2-y2
dxy
dyz
ligand lone pair ed-orbital electrons
crystal field splitting 
colors
electrostatic repulsion
dxz
colors
560 nm
580 nm
490 nm
620 nm
430 nm
800 nm
400 nm
[Ti(H2O)6]3+
red
eg
dz2

h
510 nm
t2g
dxy
dx2-y2
dyz
dxz
E = hc = h

spectrochemical series
CN- > NO2- > en > NH3> H2O > OH- > F- > Cl- > Br- > Istrong field
large 
as charge increases,  increases
weak field
small 
colors
eg
eg

t2g
t2g
low spin
high spin
high spin d5
[Zn(en)3]2+ d10 Sc3+ d0
colorless
weakly colored
spectrochemical series
CN- > NO2- > en > NH3> H2O > OH- > F- > Cl- > Br- > Istrong field
large 
weak field
small 
colors
coordination number = 4
tet =
4
9
oct
always high spin
tetrahedral
dz2
dx2-y2
dxy
dyz
square planar
dx2-y2
dxy
dz2
dyz
dxz
dxz
colors
coordination number = 2
linear
dz2
ligands along z-axis
dyz
dxz
dxy
dx2-y2
magnetic properties
compounds with unpaired e[Fe(CN)6]4-
paramagnetic
[Fe(H2O)6]2+
eg
eg
t2g
t2g
diamagnetic
paramagnetic
Guoy balance
spectrochemical series
CN- > NO2- > en > NH3> H2O > OH- > F- > Cl- > Br- > Istrong field
large 
weak field
small 
magnetic properties
compounds with unpaired efor ≤ 5 unpaired e-
paramagnetic
 (BM) =  n(n+2)
[Fe(H2O)6]2+
eg
µ = √ 24
µ = 4.90
Guoy balance
t2g
spectrochemical series
CN- > NO2- > en > NH3> H2O > OH- > F- > Cl- > Br- > Istrong field
large 
weak field
small 
Coordination Complexes
20 Questions
mineral
yes
vegetable
yes
animal
yes
Fe2+
+ O2
strong field
- O2
weak field
red
blue