2. CONTENT
ORD
PRINCIPLE
FUNDAMENTAL OF ORD
CD
COTTON EFFECT
ORD CURVES
APPLICATION
DIFFERENCE B/W ORD & CD
CONCLUSION
3. ORD
ORD is technique related to the optical
activity
Rate of change of specific rotation
with change in wave length
Optical rotation caused by compound
changed with wavelength of light was
first denoted by Biot in 1817
4. FUNDAMENTAL OF ORD
Plane polarized light
Optical activity
Specific rotation
Circular birefringence
Optical rotation
Elliphicity
5. Plane polarized light
Light from ordinary lamp consists of
waves vibrating in many different
planes
It is passed through Polaroid lens it is
found to be vibrate in one plane is said
to be plane polarized light
7. OPTICAL ACTIVITY
The compounds which are having the
ability to rotate the plane of polarized
light are called optical active
compound
This property of compounds is called
optical activity
Measured by Polarimeter
Dextrorotatory
Levorotatory
9. SPECIFIC ROTATION
The specific rotation ([α]) is
an intensive property of a chemical
compound, defined as the change in
orientation of the plane of linearly
polarized light as this light passes
through a sample with a path length of
1 decimeter and a sample
concentration of 1 gram per 1 millilitre
It is denoted by [α]
10. CIRCULAR
BIREFRINGENCE
Birefringence is the optical property
of a material having a refractive
index that depends on
the polarization and propagation
direction of light
α= (nL-nR)π/ α
11. CIRCULAR DICHORISM
Some material posses special properties of
absorption of the light circularly light to
different extent than the right circulary
polarized light
Chiral or asymmetric compounds produce
CD spectrum
12. COTTON EFFECT
This phenomenon
was discovered in
1895 by the French
physicist Aimé
Cotton
Combination of
circular dichorism
& circular
birefringence
13. ORD CURVES
Plain curves
Anomalous curves
single cotton effect curves
multiple cotton effect curve
14. PLAIN CURVES
Normal smooth curves
Do not cross the zero rotation line
e.g.:- alcohols hydrocarbons
16. SCEC & MCEC
Two or more peaks
& trough
e.g. ketosteroids
camphor
17. APPLICATION
CD/ORD of protein
Qualitative analysis of molecules
Enzyme co-factor evaluation
CD/ORD of proteins
CD as finger printing
CD/ORD of nucleic acids
CD of B-DNA is different as compared to A-
DNA
Evidence for base stacking
18. CD/ORD of proteins
e.g:- L-lysine
Positive CD at 217nm
Negative CD at 197nm
Random coil :- ph 5.2
Alpha helical :- ph 11.0
21. CD as finger printing
It acts as finger printing technique for
trace amount of carbohydrate meterial
E.g. dermatan sulphate
heparitin sulphate
E.g :- pectin in the presence of citric
acid& sucrose
23. BASE STACKING
ORD spectrum of Polycytidylic acid
shows at 292nm is 35,160deg/M/cm
HELICITY DETERMINED BY
Formaldehyde
Ethylene glycol
24. DIFFERENCE B/W ORD &
CD
ORD CD
PLANE POLARIZED LIGHT
DISPERSIVE PHENOMENA
PLANE POLARIZED IS USED &
IS NOT CONVERTED TO
ELLIPTICAL LUGHT
GRAPHS ARE OBTAINED BY
SPECIFIC ROTATION V/S
WAVELENGTH
CIRCULARLY POLARIZED
LUGHT
ABSORPTIVE PHENOMENA
CIRCULAR POLARIZED LIGHT IS
USED & IS CONVERTED TO
ELLIPICITY
GRAPHS ARE OBTAINED
MOLAR ELLIPICITY V/S WAVE
LENGTH