A

Project Report
ON

SPECTRO ANALYSIS OF COMPOUND

Submitted
in partial fulfillment
for the award of the Degree of
Bachelor of Science
in Department of Chemistry
Guided by: Submitted by:
Dr. Mukesh Kumari Balwant
(Assistant Professor)
NIMS INSTITUTE OF ENGINERERIG AND TECHNOLOGY
NIMS UNIVERSITY, RAJASTHAN (JAIPUR) (303121)
 CERTIFICATE
This is to certify that the project titled “SPECTRO ANALYSIS OF
COMPOUND” submitted by Mr. Balwant partial fulfillment of the
course work requirement for B.Sc. Program in the NIMS Institute
of Engineering and Technology is a bonafide belief work carried
out by him under my guidance and supervision. This project report
has been found quite satisfactory.
 ACKNOWLEDGEMENT

First of all, I would like to thank my professor. Dr. Mukesh Kumari for
helping me to acquire some basic knowledge of “Spectro Analysis of
Compound”. At the same time, she gave me the opportunity to learn
something new related to spectra analysis, chemical analysis compound
etc.
Introduction of Spectroscopy :
It
deals with “The interaction of Electromagnetic Radiations with
Matter/Molecules” . This is a very powerful method to find out structure
of any compound. Now in present day many types of spectroscopy used
but there we will disscus three types
1) H NMR
1

2)Infrared (IR)
3)Mass spectroscopy

Use of these three methods we will to explain structures of given

organic compound.
Introduction to Nuclear Magnetic Resonance
NMR (H ) :-1

NMR spectroscopy is a absorption spectroscopy.

Under appropriate condition in a magnetic field a sample absorb
electromagnetic radiations in the radio frequency region. Those nuclei
absorb electromagnetic radiation these are called NMR active nuclei.
All nuclei carry a charge. In some nuclei this charge spine on
the nuclear axis (shown in fig.) and this circulation of nuclear charge
generate a magnetic dipole along the axis. This is called precession
frequency generated by nucleus. Only those electromagnetic radiation
absorb or NMR active nuclei when precession frequency of nucleus is
exactly equal to the frequency of the EM radiation.
The precession of a spinning nucleus due to the applied magnetic field.
The spinning of nuclear charge produce angular momentum. This angular
momentum can be described in terms of “Quantum Spin
1
Number(I)” ,where “I” have values 0, 2 ,1 so on. On the basis of nuclear
structure the value of I is in table
Atomic Number Atomic Mass I value Example
5
Odd or Even Odd H ¿), O ( )
1 1 17
2 n 1 8
2
Odd Even n 2
1H (1), N (1)
14
7

Even Even 0 12
6
16
C , 8O

The nuclei which have I=0 value these are NMR inactive. In quantum
mechanical terms; the spin number I determines the number of
orientations a nucleus may assume in an external uniform magnetic field
in accordance with the formula 2I+1.
Energy Calculation:-
The exact amount of the radio frequency energy
needed for resonance depends upon the strength of the external
magnetic field and on the nucleus being irradiated,
h
∆E=hv=Ύ 2 π B 0

Where, ∆E- Energy difference between two spin state of Proton,

h – Plank’s constant,
Ύ- Gyromagnetic ratio (For a proton Ύ=26,750)
Variation of Energy Separation between Nuclear Spin State as a Function of Applied Field Strength .

NMR SPECTROMETER
The schematic diagram of an CW NMR spectrometer is shown in Fig. It
consists of the following parts:
1) A powerful electromagnet whose strength can be varied.
2) A radiofrequency generator.
3) A detector which monitors the absorption of energy and amplifies
the electronic signal.
4) A recorder which records the spectrum on a chart paper which is
calibrated in frequency and ppm units.
5) A 5mm wide long sample tube.
REFERENCE COMPOUND:
The most generally useful reference compound is tetra methyl silane
(TMS) Si(CH ¿ ¿ . This has several advantages;
3 4

1) It is chemically inert , symmetrical, volatile (B.P. 25℃).

2) It gives a single, intense, sharp absorption peak.
3) Its proton are more shielded than almost all organic proton.

CHEMICAL SHIFT:
The shift in the position of PMR signals
resulting through shielding and de -shielding by circulation of electrons
in chemical bonds is called the chemical shift.
Unit of expression of chemical shift is Part Per Million (ppm).

COUPLING CONSTANT:
The distance between the adjacent peaks in
a multiplet is called the coupling constant. It is denoted by “J”. It is a
quantitative measure of effectiveness of spin- spin coupling. It is
expressed in Hz and independent of applied field strength B .0
SCALES OF THE CHEMICAL SHIFT:
In terms of ppm, the chemical shift are expressed
in the following two scales, i.e.,
1) The δ (delta) scale; where
6
∆ v ( Hz )∗10
δ = Oscillator frequency( MHz)

2)The τ (tau) scale, where

τ =¿ 10-δ

INFRARED SPECTROMITRY (IR):-

IR is an absorption spectroscopy.
IR radiation refers broadly to that part of the electromagnetic spectrum
between the visible and microwave regions.
 The IR region which extends from (12500-4000cm ) is called
−1

the near IR region, that which extends from (4000-667cm ) is called the
−1

ordinary IR region and that which extends from (667-50cm ) is called the
−1

far IR region.

NEAR IR ORDINARY IR FAR IR

12500 - 4000 cm −1
4000 - 667 cm−1
667 – 50 cm −1

Principle Of IR Spectroscopy:-
“The absorption in the IR region occurs due to
excitation of molecule from the lower to the higher vibrational level”.
Since each vibrational level is associated with a number of closely spaced
rotational levels, IR spectra may be regarded as vibrational – rotational
spectra.
The atoms in a molecule are not ridigly held but keep on
vibrating to and fro about an average inter – nuclear distance. Thus each
bond has a native stretching and bending frequency. Which is not
change. But when IR radiation absorb molecule and get excited in higher
vibrational level than amplitude increase of native frequency.
All the bonds in a molecule are not capable of absorbing
IR radiation even if the frequency of incident radiation exactly matches
the native frequency of the bond. Only those bonds, which are
accompanied by a change in dipole moment will absorb in the IR region.

CALCULATION OF VIBRATIONAL FREQUENCY:

The frequency of the stretching
vibration of any bond can be calculated fairly accurately by the
application of Hook’s law-

V= 1
2π √ k
μ

Where,
K – Force constant
m1∗m2
μ=¿ Reduce mass of molecule; μ=
m1 +m2

IR SPECTROMETER:
 The modern double beam IR spectrometer consists
of four main parts :
1) Radiation Source: The most common source of IR radiation is the
Nernst glower which consists of a rod of sintered mixture of oxides
of Zirconium Ytterium and Erbium.
2) Monochromator: To obtain monochromatic radiations, optical
prism are used.
3) Cell containers: The most commonly used material for the cell
containers of the prism is NaCl since it is transparent to IR radiations
down to 625cm .−1

4)Detectors: Most of the modern instruments use thermopile

detectors. These work on the principle of thermocouple.

Flow-sheet diagram of a double beam IR spectrometer.

Part of IR Spectrum:
 IR spectrum divided into two parts:-
1) Functional group region: This portion is extended from (4000-1400
cm ). Almost all the functional groups absorb in this region.
−1

2) Finger Print Region: Most of the absorption bands cannot be

analyses completely. But a peak by peak correspondence in the IR
spectra of two different samples is an excellent criteria of identify.
So this region is called Finger Print Region. It is extended from
(1400-900cm ) −1

Characteristic Absorption of Various Functional Groups:

Types of vibration Class of compound Approximate Intensity

range (cm )
−1

C-H ( stretch ) Alkanes 2900-2853 cm −1

s
Alkenes 3100-3010 cm −1
s
Alkynes 3150-3052cm −1
s
3300
Aldehydes s
C=C ( stretch ) Alkenes 1680-1600 cm −1
w
C≡C ( stretch ) Alkynes, Aromatic 1600-1450 cm −1
w
C=O ( stretch ) Aldehydes 1740-1720 cm −1
s
Ketones 1725-1705 cm −1
s
Carboxylic acids 1725-1700 cm −1
s
Amides 1680-1630 cm −1
s
O-H ( stretch ) Phenols 3650-3590 cm −1
s
Carboxylic acids 2700-2500cm −1
w
3500
N-H ( stretch ) 1 - Amines
0
m
2 - Amines 3500-3310 m
0
MASS SPECTROMETRY:-

It is not a true spectroscopy technique

because absorption of electromagnetic energy is not involve in any way.
Mass spectrometry is used to characterize organic molecules in two
principal ways:
1) To measure exact molecular weights, and from this, exact molecular
formula can be determined.
2) To indicate within a molecule the points at which it prefers to
fragment, from this, the presence of certain structural units in the
organic compound can be recognized.
Principle Of Mass Spectrometry:
Based on Newton’s second law of motion and
momentum, a mass spectrometer uses this property of matter to plot
ions of varying masses on a mass spectrum. From the law, we infer how
much mass is relevant to the inertia and acceleration of a body. This
principle is applied to the aspect where ions with different mass to
charge ratios are deflected by different angles in an electric or magnetic
field.

Mass Spectrum:
A mass spectrum is a graph obtained by
performing mass spectrometry. It is a relation between the mass to
charge ratio and ion signal.

Mass spectrometers for structure elucidation can be

classified according to the method of separation the
charged partical:
A)Magnetic Field Deflection
1) Magnetic Field Only.
2)Double Focusing.
B) Quadrupole Mass Spectrometry.
1)Quadrupole Mass Filter.
2) Quadrupole Ion Stroage (Ion Trap).
 C) Time of Flight.
D) FT-ICR (Ion Cyclotron Resonance).
E) Tandem Mass Spectrometry.

Mass Spectrometry Instrumentation:

Four main parts of mass spectrometry are discussed below:
1) Ionizer – The bombarding of the sample is done by the electrons.
These electrons move between cathode and anode. When the
sample passes through the electron stream between the cathode
and anode, electrons with high energy knock electrons out of the
sample and form ions.
2)Accelerator – The ions placed between a set of charged parallel
plates get attracted to one plate and repel from the other plate. The
acceleration speed can be controlled by adjusting the charge on the
plates.
3)Deflector – Magnetic field deflects ions based on its charge and
mass. If an ion is heavy or has two or more positive charges, then it
is least deflected. If an ion is light or has one positive charge, then it
is deflected the most.
4)Detector – The ions with correct charge and mass move to the
detector. the ratio of mass to charge is analyzed through the ion
that hits the detector.
Mass spectrometry Diagram:

Mass Spectrometry Instrumentation

IDENTIFICATION OF UNKOWN COMPOUND:-

H
1
NMR Data of Compound:-

NMR Graph of Compound

Parameter Value Parameter Value
v CH 5 j 25
3

688.561(1) 0.610(1)
v0
2106.551(1) d
(H,CH )
4j 3 -0.702(1)
vm 5 J (CH 3)
2130.281(1) 0.329(1)
vp 6 j (CH 3)
2102.784(2) -0.602(2)
3 j 21
7.655(2) e
Transition cald 566
3 j 34
7.417(2) Transition 408
assigned
4 j 26
1.902(3) Peak observed 147

Analysis of Spectra-
1) In the table H NMR spectral parameters are given for a
1

compound in dilute solution of CS . The graph illustrates the

2

computed and observed H NMR spectra of the methyl proton.

1

2) The δ 7.70−7.70 region was expanded to show the coupling

pattern of 5 aromatic hydrogen.
3) From data shown that compound having an aromatic ring
and methyl as a side substitute.
IR Spectra of Compound-

Analysis of graph of compound-

1) Absorption at wavenumber 3300 cm ¿ 3100 cm is typical of
−1 −1

stretching vibration of aromatic compounds.

2) Around wavenumber 2940 cm is an absorption band due to C-H
−1

vibrations in the side chain methyl group aromatic ring.

3) In the wave number 1440 to 1625 cm region are band of
−1

absorption due to vibration of the C=C bonds in the aromatic

ring.
 4) The complex IR absorption pattern around 700cm is a typical −1

of aromatic compound with just one substituent group.

5) There are no other specific absorption for any functional
group group.

Mass Spectra of Compound-

Mass Spectra Data Table-

m/z value of 91 65 63 51 50 39
+¿¿
[Fragment ]
C H C5 H5 C5 H3 C4 H3 C4 H2 C3 H3
Molecular 7 7

fragment
Analysis of Data -
 1)The mass spectrum of compound is shown. The spectrum displays a
strong molecular ion at m/e = 92, small and m+2 peaks, a base
peak at m/e = 91 and an assortment of minor peaks m/e = 65 and
below.
2) [ M ] is the molecular ion peak (M) with an m/z of 92 if an aromatic
+¿¿

ring having than corresponding to ¿, the original molecule minus an

electron, ¿.
3)The small M peak at m/z 93, corresponds to an ionised aromatic
+¿¿

molecule with one 13 atom in it i.e. an ionised molecule of formula

C

¿ ¿ ¿.

Result:-
To analysis NMR,IR and MASS spectra the given compound
having an aromatic ring and a side substitute methyl, not having any
other functional groups .
So
“The given compound is an aromatic compound Toluene”