1.
Transition Metals and Coordination
Chemistry
Chapter 23Chapter 23

2.
Transition Metals
SimilaritiesSimilarities within a given periodwithin a given period
andand within a given group.within a given group.
Last electrons added are inner electrons (Last electrons added are inner electrons (dd’s,’s, ff’s).’s).

3.
20_431
Ce
Th
Pr
Pa
Nd
U
Pm Sm
Pu
Eu
Am
Gd
Cm
Tb
Bk
Dy
Cf
Ho
Es
Er
Fm
Tm
Md
Yb
No
Lu
Lr
Sc
Y
La
Ac
Ti
Zr
Hf
Unq
V
Nb
Ta
Unp
Cr
Mo
W
Unh
Mn
Tc
Re
Uns
Fe
Ru
Os
Co
Rh
Ir
Ni
Pd
Pt
Cu
Ag
Au
Zn
Cd
Hg
Uno Une Uun Uuu
Np

4.
20_432
Sc
Y
La*
Ac†
Ti
Zr
Hf
Unq
V
Nb
Ta
Unp
Cr
Mo
W
Unh
Mn
Tc
Re
Fe
Ru
Os
Co
Rh
Ir
Ni
Pd
Pt
Cu
Ag
Au
Zn
Cd
Hg
Ce
Th
Pr
Pa
Nd
U
Pm
Np
Sm
Pu
Eu
Am
Gd
Cm
Tb
Bk
Dy
Cf
Ho
Es
Er
Fm
Tm
Md
Yb
No
Lu
Lr
d-block transition elements
*Lanthanides
† Actinides
f-block transition elements
Uns Uno Une Uun Uuu

5.
20_435
0.2
Atomicradii(nm)
Atomic number
La
Hf
Ta
W
Re Os
Ir Pt
Au
Zr
Y
Nb
Mo
Tc Ru
Rh Pd
Ag
Sc
Ti
V
Cr
Mn Fe Co Ni
Cu
1st series (3d)
2nd series (4d)
3rd series (5d)
0.1
0.15

6.
Multiple Oxidation States

7.
Metallic Behavior/Reducing Strength
Lower oxidation state = more metallicLower oxidation state = more metallic

8.
Color and Magnetism
e-
in partially filled d sublevel absorbs visible light
moves to slightly higher energy d orbital
Magnetic properties due to unpaired electrons

9.
Electronegativity increases down column

10.
Chromium
Chemical properties reflect oxidation state

11.
Valence-State Electronegativity
Electronegativity, ENElectronegativity, EN::
electron “pulling power”electron “pulling power”
Valence-state ENValence-state EN::
metal in higher oxidation statemetal in higher oxidation state
is more positiveis more positive
has stronger pull on electronshas stronger pull on electrons
is more electronegativeis more electronegative
““Effective ENEffective EN””

12.
Manganese

13.
Silver

14.
Weak Reducing Agent, H2Q

15.
Mercury

16.
Coordination Compound
Consist of aConsist of a complex ioncomplex ion and necessaryand necessary counter ionscounter ions
[Co(NH[Co(NH33))55Cl]ClCl]Cl22
Complex ion:Complex ion: [Co(NH[Co(NH33))55Cl]Cl]2+2+
CoCo3+3+
+ 5 NH+ 5 NH33 + Cl+ Cl--
== 1(3+) + 5 (0) + 1(1-)1(3+) + 5 (0) + 1(1-)
= 2+= 2+
Counter ions:Counter ions: 2 Cl2 Cl--

17.
Complex ion remains intact upon dissolution in water
[Co(NH3)6]Cl3 [Pt(NH3)4]Br2

18.
Complex Ion
Species where transition metal ion is surroundedSpecies where transition metal ion is surrounded
by a certain number of ligands.by a certain number of ligands.
Transition metal ion:Transition metal ion: Lewis acidLewis acid
Ligands:Ligands: Lewis basesLewis bases
Co(NHCo(NH33))66
3+3+
Pt(NHPt(NH33))33BrBr++

19.
Ligands
Molecule or ion having a lone electron pair thatMolecule or ion having a lone electron pair that
can be used to form a bond to a metal ioncan be used to form a bond to a metal ion
((Lewis baseLewis base).).
coordinate covalent bondcoordinate covalent bond: metal-ligand bond: metal-ligand bond
monodentatemonodentate: one bond to metal ion: one bond to metal ion
bidentatebidentate:: two bond to metal iontwo bond to metal ion
polydentatepolydentate:: more than two bonds to a metalmore than two bonds to a metal
ion possibleion possible

20.
Formulas of Coordination Compounds
1.1.Cation then anionCation then anion
2.2.Total charges must balance to zeroTotal charges must balance to zero
3.3.Complex ion in bracketsComplex ion in brackets
KK22[Co(NH[Co(NH33))22ClCl44]]
[Co(NH[Co(NH33))44ClCl22]Cl]Cl

21.
Names of Coordination Compounds
1.1.Cation then anionCation then anion
2.2.LigandsLigands
in alphabetical order before metal ionin alphabetical order before metal ion
neutral:neutral: molecule name*molecule name*
anionic:anionic: -ide-ide →→ -o-o
prefix indicates number of eachprefix indicates number of each
3.3.Oxidation stateOxidation state of metal ion in () only if moreof metal ion in () only if more
than one possiblethan one possible
4.4.If complex ion = anion, metal endingIf complex ion = anion, metal ending →→ -ate-ate

22.
Examples
KK22[Co(NH[Co(NH33))22ClCl44]]
potassium diamminetetrachlorocobaltate(II)potassium diamminetetrachlorocobaltate(II)
[Co(NH[Co(NH33))44ClCl22]Cl]Cl
tetraamminedichlorocobalt(III) chloridetetraamminedichlorocobalt(III) chloride

23.
20_441
Isomers
(same formula but different properties)
Stereoisomers
(same bonds, different
spatial arrangements)
Structural
isomers
(different bonds)
Optical
isomerism
Geometric
(cis-trans)
isomerism
Linkage
isomerism
Coordination
isomerism

24.
Structural Isomerism 1
Coordination isomerism:Coordination isomerism:
Composition of the complex ion varies.Composition of the complex ion varies.
[Cr(NH[Cr(NH33))55SOSO44]Br]Br
andand [Cr(NH[Cr(NH33))55Br]SOBr]SO44

25.
Structural Isomerism 2
Ligand isomerism:Ligand isomerism:
Same complex ion structure but point ofSame complex ion structure but point of
attachment of at least one of the ligands differs.attachment of at least one of the ligands differs.
[Co(NH[Co(NH33))44(NO(NO22)Cl]Cl)Cl]Cl
andand [Co(NH[Co(NH33))44(ONO)Cl]Cl(ONO)Cl]Cl

26.
Linkage Isomers
[Co(NH[Co(NH33))55(NO(NO22)]Cl)]Cl22
Pentaamminenitrocobalt(III)Pentaamminenitrocobalt(III)
chloridechloride
[Co(NH[Co(NH33))55(ONO)]Cl(ONO)]Cl22
Pentaamminenitritocobalt(III)Pentaamminenitritocobalt(III)
chloridechloride

27.
Stereoisomerism 1
Geometric isomerism (cis-trans):Geometric isomerism (cis-trans):
Atoms or groups arranged differently spatiallyAtoms or groups arranged differently spatially
relative to metal ionrelative to metal ion
Pt(NHPt(NH33))22ClCl22

28.
20_444
H3N
Co
H3N
NH3
NH3
Cl
Cl
H3N
Co
H3N
NH3
Cl
Cl
NH3
Cl
Cl
Co
Cl
Cl
Co
(a) (b)

29.
Stereoisomerism 2
Optical isomerismOptical isomerism::
Have opposite effects on plane-polarized lightHave opposite effects on plane-polarized light
(no superimposable mirror images)(no superimposable mirror images)
20_446
Unpolarized
light
Polarizing
filter
Polarized
light
Tube
containing
sample
θ
Rotated
polarized light

30.
20_448
Left hand Right hand
Mirror image
of right hand

31.
20_449
N
N
N
N
N
N
Co
N
N
N
N
N
N
Co
Mirror image
of Isomer I
Isomer I Isomer II
N
N
N
N
N
N
Co

32.
20_450
Cl
Cl
N
N
N
N
Co
Cl
Cl
N
N
N
N
Co
Cl
Cl
N
N
N
N
Co
Cl
Cl
N
N
N
N
Co
Cl
Cl
N
N
N
N
Co
Isomer IIIsomer I
cistrans
Isomer II cannot be
superimposed exactly
on isomer I. They are
not identical structures.
The trans isomer and
its mirror image are
identical. They are not
isomers of each other.
Isomer II has the same
structure as the mirror
image of isomer I.(b)(a)

33.
Crystal Field Theory
Focus:Focus: energies of theenergies of the dd orbitalsorbitals
AssumptionsAssumptions
1.1.Ligands:Ligands: negative point chargesnegative point charges
2.2.Metal-ligand bonding:Metal-ligand bonding: entirely ionicentirely ionic
strong-fieldstrong-field (low-spin): large splitting of(low-spin): large splitting of dd orbitalsorbitals
weak-fieldweak-field (high-spin): small splitting of(high-spin): small splitting of dd orbitalsorbitals

34.
20_454
∆
eg(dz2, dx2
– y2
)
t2g(dxz, dyz, dxy)
Free metal ion
3d orbital
energies
E
∆ = crystal field splitting

35.
High spin Low spin

36.
[V(H2O)6]2+
[V(H2O)6]3+
[Cr(NH3)6]3+
[Cr(NH3)5Cl]2+s

37.
20_459
–
–
–
–
–
–– –
–
–
dz2 dx2 – y2
dxy dyzdxz
(a) (b)
Tetrahedral Complexes

38.
20_461
E
Free metal ion Complex
dz2
dxy
dxz dyz
dx2 - y2
M z
(b)
Free metal ion Complex
dx2 - y2
dxy
dz2
dxz dyz
M
(a)
x
y
E
Square Planar & Linear Complexes
Approach along x-and y-axes Approach along z-axis

39.
Hemoglobin & Oxyhemoglobin