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Pengantar Kimia Koordinasi
Kimia Anorganik II
COMPOUNDS
NOMENCLATURE
[Co(NH3)3(NO2)3]
Triamintrinitrokobalt (III)
[Pt(NH3)2Cl2]
Diamindikloroplatina (II)
[Ni(DMG)2]
Bisdimetilglioksimatonikel (II)
[Cr(NH3)6](NO3)3
Heksaminkromium (III) nitrat
[Co(NH3)5H2O]Cl3
Akuopentaminkobalt (III) klorida
[Pt(NH3)4NO2Cl](SO4)2
Tetraminkloronitroplatina (IV) sulfat
K3[Al(C2O4)3]
Kalium trioksalatoaluminat (III)
NH4[Cr(NH3)2(NCS)4]
Ammonium diamintetratiosianatokromat (III)
Ca2[Fe(CN)6]
Kalsium heksasianoferrat (II)
d-Orbitals and Ligand
Interaction
(Octahedral Field)
Ligands
approach
metal
d-orbitals pointing directly at axis are
affected most by electrostatic interaction
d-orbitals not pointing directly at axis are least
affected (stabilized) by electrostatic interaction
The six negative charges are equally distributed
in a sphere around the metal
Crystal Field Theory (CFT)
6Dq = 0.6 o 4Dq = 0.4 o
High Spin Vs. Low Spin (d1 to d10)
Electron Configuration for Octahedral complexes of metal ion having d1 to
d10 configuration [M(H2O)6]+n.
Only the d4 through d7 cases have both high-spin and low spin configuration.
Electron configurations for
octahedral complexes of
metal ions having from d1
to d10 configurations. Only
the d4 through d7 cases
have both high-spin and
low-spin configurations.
CFSE
(Crystal Field Stabilization Energy)
Octahedral complexes, weak field ligand, high spin
complexes
n
Konfiguration
1
2
3
4
5
6
7
8
9
10
t2g1
t2g2
t2g3
t2g3
t2g3
t2g4
t2g5
t2g6
t2g6
t2g6
eg1
eg2
eg2
eg2
eg2
eg3
eg4
Unpair electron
1
2
3
4
5
4
3
2
1
0
CFSE
-4Dq
-8Dq
-12Dq
-6Dq
0Dq
-4Dq + P
-8Dq + 2P
-12Dq + 3P
-6Dq + 4P
0Dq + 5P
Octahedral, Tetrahedral & Square
Planar
CF Splitting pattern for various
molecular geometry
dx2-y2 dz2
dx2-y2
Octahedral
Tetrahedral
M
dxy dyz dxz
M
Square planar
dxy
M
dz2
dxy dyz dxz
Pairing energy Vs. 
Weak field  < Pe
Strong field  > Pe
dx2-y2 dz2
Small   High
Spin
dxz dyz
Mostly d8
(Majority Low spin)
Strong field ligands
i.e., Pd2+, Pt2+, Ir+, Au3+
Color Absorption of Co3+ Complexes
The Colors of Some Complexes of the Co3+ Ion
Complex Ion
Wavelength of
light absorbed
Color of Light
Absorbed
Color of Complex
[CoF6] 3+
700 (nm)
Red
[Co(C2O4)3] 3+
600, 420
Yellow, violet
Dark green
[Co(H2O)6] 3+
600, 400
Yellow, violet
Blue-green
[Co(NH3)6] 3+
475, 340
Blue, violet
Yellow-orange
[Co(en)3] 3+
470, 340
Blue, ultraviolet
Yellow-orange
[Co(CN)6] 3-
310
Ultraviolet
Pale Yellow
Green
The complex with fluoride ion, [CoF6]3+, is high spin and has one absorption band.
The other complexes are low spin and have two absorption bands. In all but one
case, one of these absorptions is in the visible region of the spectrum. The
wavelengths refer to the center of that absorption band.
Colors & How We
Perceive it
650
580
800
560
400
Artist color wheel
showing the colors which
are complementary to one
another and the wavelength
range of each color.
430
490
Black &
White
When a sample absorbs light, what we see is the sum
of the remaining colors that strikes our eyes.
If a sample absorbs all wavelength
of visible light, none reaches our
eyes from that sample.
Consequently, it appears black.
If the sample absorbs no
visible light, it is white
or colorless.
Absorption and Reflection
If the sample
absorbs
all but orange, the
sample appears
orange.
Further, we also perceive orange color
when visible light of all colors except blue
strikes our eyes. In a complementary
fashion, if the sample absorbed only
orange, it would appear blue; blue and
orange are said to be complementary
colors.
650
580
750
400
560
430
490
Light absorption Properties of Metal
Complexes
Recording the absorption Spectrum
Complex Influence on Color
Compounds of Transition metal complexes solution.
650
800
400
430
[Fe(H2O)6]3+
[Ni(H2O)6]2+
[Co(H2O)6]2+
[Zn(H2O)6]2+
[Cu(H2O)6]2+
580
560
490
Determine the field strength by
measuring absorbed energy
Spectrophotometry method
E
Absorbancy
h.c

Absorded
energy is
energy used for
exitation or the
electrons from
t2g to tg
 max
wavelength
TEORI ORBITAL MOLEKUL
• Graphically these two orbitals look like this:
53
Constructive
Overlap
of two 1s orbitals
Destructive
Overlap of two
1s orbitals
54
Bonding orbital
Anti-bonding orbital
Lower energy
Higher energy
Stable
Unstable
Favorable for electrons
Unfavorable for electrons
Electrons exist between nuclei
Electrons exist outside
55
•
Energetically, the molecular orbitals split.
1. The 1s lies lower in energy.
2. The 1s* is higher in energy.
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•
The head-on overlap of two corresponding p atomic orbitals
on different atoms, such as 2px with 2px, produces:
1.
bonding orbital
2.
σ 2pxantibonding orbital
σ* 2px
57
• Graphically, these orbitals look like this:
58
• Graphically these orbitals look like this:
59
*2px
*2py
*2pz
2p
2p
2px
2py
N
2pz
*
 2s
2s
2s
2s
N
7 electrons + 7 electrons
*
 1s
1s
1s
1s
60
Orbital Molekul [Co(NH3)6]3+
61
Orbital Molekul [CoF6]3-
62
63
64
65
66
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