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1. Co-Ordination
Compounds
Name :- RISHI RAM MAHATO
Exam Roll No :- 14SCHE024547
Class Roll No :- 146
Session :- 2014-17

2. Introduction
 Coordination refers to the "coordinate covalent bonds" (dipolar
bonds) between the ligands and the central atom. Hence, in this
type of compounds a electron rich species donates its electron
pair/pairs to the electron deficient species.

3.  Coordination complexes have been known since the
beginning of modern chemistry. Early well known
coordination complexes include dyes such as Prussian
blue.
 In 1869, WILHELM BLOMSTRAND proposed the
COMPLEX ION CHAIN THEORY.
 Again it was improved by SOPHUS JORGENSEN.
*Alfred Warner was first to publish the
most accepted theory of Complexes in 1893.
History

4. Occurrence
Chlorophyll :- It’s a complex of Mg(II) directly
coordinated with Nitrogen with large Organic entity.
 Found in Leaves & Green parts of Plants.
 Plays vital role in existence of Living Things.

5. Hemoglobin :- It is Complex of Fe(II) directly linked to
Nitrogen atoms of large organic entity (HEME structure).
 This species is responsible for Red Coloration of Blood.
 It maintain the pH of the Blood as well.

6. Cytochrome :- Cytochromes are iron containing hemeproteins
central to which are heme groups that are primarily responsible for the
generation of ATP via electron transport.
 They are found either as monomeric proteins (e.g., cytochrome c) or as
subunits of larger enzymatic complexes that catalyze redox reactions.

7. Fluorite (also called fluorspar) :- is the mineral form of
calcium fluoride, CaF2. It belongs to the halide minerals. It crystallizes
in isometric cubic habit, although octahedral and more complex
isometric forms are not uncommon. Fluorite is a colorful mineral, both
in visible and ultraviolet light, and the stone has ornamental and
lapidary uses.

8. Types
 According to their Geometry, These are classified as
 Linear for 2 coordination
 Trigonal planar for 3 coordination
 Tetrahedral or square planar for 4 coordination

9.  Trigonal bipyramidal or square pyramidal for 5
coordination
 Octahedral (orthogonal) for 6 coordination

10. Pentagonal Bipyramidal, capped octahedral or capped
trigonal prismatic for 7 coordination
Square antiprismatic or dodecahedral for 8 coordination

11. Electrostatic model for bonding in transition metal
complexes.
Accounts for observed properties of transition metal
complexes.
Focuses on d-orbitals.
Ligands = point charges in case of anions or dipoles in case
of neutral molecules.
Assumes metal ligand bond to be ionic.
Crystal Field Theory

12. Electrostatic Interactions
(+) metal ion attracted to (-) ligands (anion or dipole
provides stability
lone pair e-’s on ligands repulsed by e-’s in metal d
orbitals interaction called crystal field influences d
orbital energies
(not all d orbitals influenced the same way)

13. dx2-y2 dz2
X
Y Z
X
Y
X
Z
Y
Z
X
Greater Electrostatic Repulsion = Higher
Potential Energy
Lobes Directed At Ligands
In Tetrahedral Complexes

14. dx2-y2 dz2
dxy dxz dyz
X
X
Y
X
Z
Y
Z
X
less electrostatic repulsion = lower
potential energy
Lobes directed between ligands
In Octahedral Complexes

15. Ligands Approach Along x, y, z Axes
(-) Ligands Attracted To (+)
Metal Ion; Provides Stability
Octahedral Crystal Field
D Orbital E-’s Repulsed By (–)
Ligands; Increases D Orbital
Potential Energy
+
-
- -
-
-
-

16. Properties
Colors Of Transition Metal Complexes
1)A complex must have partially filled d subshell on metal to
exhibit color.
2)A complex with 0 or 10 d e-s is colorless.
3)Compounds/complexes that have color absorb specific
wavelengths of visible light (400 –700 nm).
4)Absorption of UV-visible radiation by atom, ion, or molecule:-
Occurs only if radiation has the energy needed to raise an
e- from its ground state to an excited state. i.e., from lower
to higher energy orbital

17. 5)wavelengths not absorbed are transmitted
6)color observed = complementary color of color absorbed
Absorbed
Color
Observed
Color

18. Application

19. Cis-Platin :-(Cisplatin, Cisplatinum, Platamin, Neoplatin, Cismaplat or
Cisdiamminedichloridoplatinum(ii) (CDDP) is a Chemotherapy Drug. It was the
first member of a class of platinum containing anticancer drugs, which now also
includes carboplatin and oxaliplatin. These platinum complexes react in the body,
binding to DNA and causing the DNA strands to crosslink, which ultimately triggers
cells to die in a programmed way.
The compound is on the World Health Organization's List of Essential Medicines, a list
of the most important medications needed in a basic health system.

20. U
T
N
K
H
A