Download Transition Metal Complexes

Transition Metal Complexes
- Structure
Coordination Sphere
Outer-sphere
Inner-sphere
What Is A Coordination Compound?
http://www.chem.purdue.edu/gchelp/cchem/
Low Coordination
Four Coordination
Common for:
1st Row metal with 
donor ligands
Four Coordination
Four Coordination
Common for:
1st Row d8 with 
acceptor ligands
2nd & 3rd Row d8
Four Coordination
Geometric
Isomerism
Five Coordination
Five Coordination
Five Coordination
Berry pseudorotation
Six Coordination
Oh
Six Coordination
D4h
D2h
D4h
D3d
Six Coordination
Seven Coordination
Eight and Higher Coordination
Polymetallic Complexes
Nomenclature Rules
1. The ligands are named first; the prefixes di,
tri, tetra, and so on are used to indicate the
number of each kind of ligand present.
[Sometimes the prefixes bis (2 ligands), tris
(3 ligands), and tetrakis (4 ligands) are also
used, especially when the ligand name is
complicated or already includes di, etc.]
Negative ligands are given names which end
in -o.
Nomenclature Rules
2. The ligand names are given in alphabetical
order. Some ligands have familiar names
also used in naming other types of
compounds (eg. chloro, cyano); others have
names special to complexes (eg. carbonato,
CO32-; aqua, H2O).
3. The name of the central metal atom or ion
followed by its oxidation state in parentheses
is given after the ligand names (not
separated by a space).
Nomenclature Rules
4. When a complex ion has a negative charge,
the name of the central metal atom is given
the ending ate.
For some of the elements, the ion name is
based on the Latin, for example, ferrate for
iron, Fe; plumbate for lead, Pb. When naming
only the ion, the word "ion" is always used in
the name.
In naming a co-ordination compound, the
name of the cation is given first as usual,
followed by the name of the anion.
Examples
K+[Pt(NH3)Cl5]potassium amminepentachloroplatinate(IV)
[Co(NH3)4SO4]+ NO3tetraamminesulfatocobalt(III) nitrate
Examples
Re2Cl82Octachlorodirhenate(III)
(H3N)5CrOCr(NH3)54+
-oxobis[pentaamminechromium(III)]
Ligand Nomenclature
Ligand
FClBrICNSCNNCSNO2ONOOH-
Name
fluoro
chloro
bromo
iodo
cyano
thiocyanato
isothiocyanato
nitro
nitrito
hydroxo
Ligand Name
O2oxo
OSO32- sulfato
(SO42-)
OSO22- sulfito
(SO32-)
CO32- carbonato
C2O42- oxalato
NH3
ammi
ne(
not
i
ce2m’
s)
H2O
aqua
CO
carbonyl
NO
nitrosyl
PR3
trialkyl- or triarylphosphine
SCN- - ambidentate ligand
Polydentate Ligands and Chelate
Some Bidentate Ligands
Ethylenediammine (en)
Acetylacetonate ion (acac)
Phenanthroline (phen)
Oxalate ion (ox)
Polydentate Ligands and Chelate
Polydentate ligand –ligand with more than one
site to connect to a metal center
Monodentate, bidentate, tridentate, ……
Chelate –polydentate ligand/metal ring
Bite Angle
•Small bite angle may distort the geometry
from ideal structure
Isomerism
Structural isomers: contain the same number and
kinds of atoms, but one or more bonds is/are different
(i.e., the connectivity between atoms is different).
There are two types of structural isomers:
coordination isomers, and linkage isomers
Stereo isomers: contain the same number and kinds of
atoms, and the same number and kinds of bonds (i.e.,
the connectivity between atoms is the same), but the
atoms are arranged differently in space. There are
two types of stereo isomers:
geometric isomers, and optical isomers
Linkage Isomerism
[Fe]-SCN
[Fe]-NCS
Geometric
Isomerism
Geometric Isomerism
facial
fac
meridional
cis
trans
Optical Isomerism
Chiral –enantiomer pair
achiral
Optical Isomerism
right hand screw
left hand screw