chapter - 5 infrared spectroscopic studies of binary...

170

CHAPTER - 5

INFRARED SPECTROSCOPIC STUDIES OF BINARY LIQUID MIXTURES

5.1 GENERAL :

Infrared spectroscopy in one of the most widely used tools for the

detection of functional groups in pure compounds and mixtures and compound

comparison. The spectrum is obtained in minutes using a few mg of the

compound which can also be recorded. Hydrogen bonding is of central

importance in the molecule science for both practical and theoretical reasons

[1-5]. Infrared spectroscopy is the leading method for identification of hydrogen

bonds [6].

The important use of FTIR spectroscopy is to determine the structure of

the compound. We know that any two compounds have not exactly the same

absorption peaks. Therefore FTIR spectra can be used as finger prints to identify

unknown compounds. FTIR spectroscopy in often used to follow the progress of

chemical the kinetics of various chemical reactions. These applications are based

on the fact that the most chemical reactions involve changes in the functional

groups. FTIR spectroscopy distinguishes between inter and intra molecular

hydrogen bonding. Free-OH group appears at (3600 to 3650 ) while

hydrogen bonded alcohols appear at lower frequency ( 3200 to 3500 )

The infrared region constitutes three parts: 1) Near infrared - The near-

infrared is approximately 1400-4000 cm-1

(2.5 – 0.8 μm). As there is less

absorption of organic molecules in this range, it is of little use for spectroscopic

purpose. 2) Mid infrared - The mid- infrared which is approximately 4000- 400

cm-1

(3.0 – 2.5 μm) may be used to study the fundamental vibrations and

associated rotational vibrational structure. Spectroscopy in this region is

extremely useful for the study of organic compounds. 3) Far infrared - The far

infrared region 400-10 cm-1

(1000-30 μm) is also not of much use for organic

spectroscopy. Since only few useful absorptions occur in the far infrared region

(400-10 cm-1

), (1000-30 μm)

171

• As bond order increases, force constant increases and frequency increases while

bond length decreases.

• The bond between heavier atoms vibrate at low frequency and stronger bond

between atoms vibrate at high frequency.

• The change in bond length or angle due to vibrational or rotational motion

causes a net change in dipole moment of the molecule.

5.2 FACTORS AFFECTING IR ABSORPTION :

The following factor which affect on IR absorption

5.2.1 HYDROGEN BONDING :

Hydrogen bonding has held particular interest in recent years due to the

central role it plays with regard to molecular recognition in both biological and

artificial systems [7-10].

When a carbonyl group is involved in hydrogen bonding its C=O stretching

frequency is lowered. The strength of hydrogen bond is at a maximum when the

proton donor group and the axis of the lone pair orbital are collinear. The strength

of the bond decreases as the distance between proton donor group and proton

acceptor group increases.

Intramolecular H- bonding shows greater effect on C=O and O–H

stretching frequencies than intermolecular H- bonding. The effect of

concentration on intramolecular and intermolecular H- bonding is markedly

different. The bands that result from intermolecular bonding generally disappear

at low concentrations. Intramolecular H- bonding persists at very low

concentrations.

IR spectroscopy is the leading method for identification of hydrogen

bonds. For instance the formation of an O-H--O hydrogen bond elongates and

weakens the O-H bond. The resulting red shift of the O-H bond stretching

frequency can be easily detected in the IR spectra and its magnitude indicates the

strength of the hydrogen bond [11].

172

The hydrogen bonding changes the C-H bond length very little and in

some cases even shortens it, leading to the blue shift of C-H bond strength

frequency. This phenomenon is called anti-hydrogen bond [12,13]. However,

Scheiner et al. [14] have concluded, from a set of careful calculations that

“antihydrogen” bonds do not differ fundamentally from conventional hydrogen

bonds. According to their results, the electron density redistribution upon

hydrogen bond formation is similar for both the C-H--O and O-H--O interactions.

The hetero aromatic compounds and their derivatives are structurally very

close to benzene. In aromatic compound, C-H stretching vibrations occur in the

region 3000-3100 cm-1

and for saturated alkane near 2950-3000 cm-1

. In

heterocyclic compounds, C-H stretching vibration bands are usually weak.

Absorption arising from C-H stretching in the alkane occurs in the general region

of 2850-3000 cm-1

.

The non hydrogen-bonded hydroxyl group of phenols absorb strongly in

the 3584-3700 cm-1

region. The sharp free hydroxyl bands are observed in the

vapour phase and in very dilute solution in non polar solvent [15].

Acidity and basicity, molecular geometry and Ring strain of the proton

donor and acceptor groups affect the strength of bonding. Hydrogen bonding is

strongest when the bonded structure is stabilized by resonance.

The hetero aromatic compounds and their derivatives are structurally very

close to benzene. In aromatic compound, C-H stretching vibrations [16] occur in

the region 3000-3100 cm-1

and for saturated alkane near 2950-3000 cm-1

. In

heterocyclic compounds, C-H stretching vibration bands are usually weak [17].

Absorption arising from C-H stretching in the alkane occurs in the general region

of 2850-3000 cm-1

.

5.2.2 INDUCTIVE EFFECTS :

Groups which have electron withdrawing inductive effects (-I ) when

attached to functional groups increase the stretching frequency. On the other

hand, group which have electron donating inductive effects (+I) when attached to

functional groups decrease the stretching frequency.

173

5.2.3 RESONANCE EFFECT :

The group which have electron withdrawing resonance effects, (-R)

when attached to functional groups, increase the stretching frequency and groups

which have electron donating resonance effects (+R) decrease the stretching

frequency.

5.2.4 STERIC EFFECT :

Steric effects also modify the stretching frequencies. When the number of

conjugated double bond increases, the effect is further increase and the further

lowering of stretching frequency takes place.

5.3 INTERPRETATION OF IR :

IR spectroscopy provides a fast and effective way to identify functional

groups present in a molecule by looking to absorptions corresponding to the bond

types present in these functional groups.

Functional group organic compounds has absorption which is characteristic

not only in position but also in largely dependent on an appreciation of the

intensities of the observed bands. Analysis of the spectrum of an unknown

compound requires the determination of the presence or absence of a few major

functional groups. The and NO2 peaks are

most conspicuous and give immediate structural information if they are present.

When assigning peaks to specific groups in the infrared region it is

usually the stretching vibrations which are most useful

174

TABLE OF SOME CHARACTERISTIC IR ABSORPTION

Frequency, cm–1

Bond Functional group

3100–3000 (s) C–H stretch aromatics

1750–1735 (s) C=O stretch esters, saturated aliphatic

1600–1585 (m) C ⃛C stretch (in–ring) aromatics

1500-1400 C ⃛C stretch (in–ring) aromatics

1320–1000 (s) C–O stretch alcohols, carboxylic acids,

900–675 (s) C–H "Bending" aromatics

3600-3650 OH Free Alcohol and Phenols

3200-3500 OH Bonded H Bonded alcohols and

phenols

3450-3600 OH Sharp Intramolecular H bond

3200-3550 OH Broad Intramolecular H bond

740-860 Ar –Cl stretch aryl halides

1050 C-O Primary alcohol

1000 C-O Secondary alcohol

1150 C-O Tertiary alcohol

1230 C-O Aromatic alcohol

175

IR Frequencies ) for pure compounds

Compound

-

strech

Aromatic

C-H

strech

Methyl

C-H

strech

Ar-Cl

strech

Ar-

strech

N-H

strech

t-Butanol 3377.47 - - - - -

Benzene - 3036.06 - - - -

Chlorobenzene - 3066.92 - 740.69 - -

Toluene - 3072.38 - - - -

o-Chlorotoluene - 3068.85 - 746.48 - -

p-Chlorotoluene - 30.3027 - 806.27 - -

o-Xylene - 3016.77

2970.48

2939.61

2920.32

- - -

m-Xylene - 3016.77 2920.29

2864.39 - - -

p-Xylene - 3022.55 2966.62

2933.83 - - -

Nitrobenzene - 3076.58 - -

1348.29

Sym

1518.03

Asym

-

Aniline - 3033.56 - - -

3356.25

Sym

3433.25

Asym

Sym = Symmetrical

Asym = Asymmetrical

176

5.4 LITERATURE SURVEY :

The presence of intramolecular hydrogen bond in o-nitroaniline was

investigated by studying the IR spectrum [18] of the compound in different proton

accepting solvents. Frequency shift of the symmetric and symmetric N-H

stretching bands showed formation of associated species with the solvents.

Analysis of shift pattern showed the presence of hydrogen bond in o-nitroaniline.

Chemical shift data for hydroxyl protons were studied [19] to calculate a

structure factor, related to an apparent number of hydrogen bonds broken, when 1,

4-dioxane was added to methanol, ethanol, 2-propanol and 2-methyl -2-propanol.

The result depends on the different content of partially unbounded OH groups in

liquid water and alcohols.

Excess dielectric polarizations, IR and NMR studies [20] of the mixtures

of ethyl iodide with benzene, toluene, o-xylene and p-xylene were carried out. IR

and NMR spectral studies supported the conclusions drawn from dielectric

polarization measurements.

The use of IR, UV-visible absorption spectroscopy was illustrated [21] to

determine thermodynamic properties and other specific chemical interactions in

alcohols.

The OH proton chemical shifts of methanol referred to the CH3 proton in

the methanol- benzene-d6 systems were measured [22] at room temperature up to

the supercritical region. MD simulations were performed at the same composition

as experiment at 575 K. The chemical shift results in the supercritical region were

in good agreement with those of pure methanol at the density within experimental

errors. The results of NMR and MD simulation suggest that the hydrogen bonded

structure of methanol was practically not affected by addition of benzene

molecule.

The thermodynamic properties of H-bonding solutions, Fourier-trans

formed infrared (FT-IR) spectroscopic investigations of 14 binary systems of the

type (alcohol or phenol) + hydrocarbon were carried out [23] at temperatures of

283, 298 and 313 K. FT-IR spectroscopy provides quantitative information on the

distribution of the alcohol molecules into the monomer and H-bonded species,

respectively. Furthermore, direct evidence on the type of H-bonded species is

177

obtained. In addition to the FT-IR data, NMR data were taken for the system

1-butanol + cychlohexane, primarily to test the infrared (IR) spectroscopic results.

The results provided a large data base for the development of thermodynamic

models of H-bonding solutions.

Brown [24] determined the IR spectrum of benzene in matrices of Kr and

Ar and showed to be strongly affected by aggregation of the benzene. The

vibrational frequencies for benzene isolated in the Ar matrix were in good

agreement with those measured in the gas phase, but the measured absolute

intensities disagreed drastically with gas phase measurements (by at least 100%).

For benzene in Kr matrices accurate absolute intensities were obtained that were

in good agreement with gas phase studies when corrected for the effective field

factor.

Adsorption of benzene and ethylbenzene on the acidic and basic sites of

beta zeolite were studied by [25]. The adsorption of benzene on Na beta and Cs

beta followed by IR spectroscopy showed two pairs of CH out-of-plane bands.

They were assigned to benzene interacting with either the cations, acidic sites or

cations. In addition species similar to liquid benzene were detected below

saturation of the adsorption sites.

Scotoni et al. [26] investigated infrared spectroscopy of CH strectching

models of partially F-substituted benzenes, and the fundamental spectrum of

fluorobenzene. They reported the study of the fundamental transitions of

fluorobenzene in the wave numbers range from about 3000 to 3150 cm-1

. They

showed, how benzene algebraic procedures must be modified for taking into

account the effects induced by the substitution of one hydrogen atom with

fluorine, i.e., (i) the reduction of symmetry and (ii) the frequency (chemical) shift

due to the change of electron distribution.

The interactions of n-heptane, benzene, and toluene with HZSM5 and

MO-HZSM catalysts were studied by [27] FTIR spectroscopy. The FTIR study

indicates that there were interactions of heptanes, benzene, and toluene with both

the strongly acidic internal OH’s and the less acidic silanol groups in HZSM5.

Thermodynamic properties of the binary systems of toluene with butyl

methacrylate, allyl methacrylate, methacrylic acid and vinyl acetate at 20, 30 and

178

40 C were reported by Wisniak et al. [28]. The C = O group of butyl

methacrylate presents and IR absorption at 1717.36 wave numbers that increases

to 1718.24 components that result in the displacement of the absorption band.

Nevertheless, the system toluene + butyl methacrylate presents negative excess

volumes, suggesting that the molecular orbital of toluene do interact with those of

the acrylic group. The C = O group of pure vinyl acetate presents an IR absorption

band at 1758.31 cm-1

, which in an equimolar mixture with toluene moves to group

of vinyl acetate is prevented from conjugation with the double bond by the

presence of an oxygen atom.

Grinvald et al. [29] reported IR Fourier spectroscopy proofs of the

existence of supramolecular structures formed by and σ hydrogen bonds in the

liquid phase of aromatic systems such as benzene and its monosubstituted

derivatives C6H5X ( X= CH3, Br, NO2) and their deuterated analogues C6D5X (X=

CD3, Br, NO2).

5.5 RESULTS AND DISCUSSION :

IR measurement for mixtures of t-butanol with aromatic hydrocarbon over

the entrie composition range has been carried out. The change in the frequencies

values –OH group in not much for the mixtures of t-butanol with toluene, p-

chlorotoluene, o-chlorotoluene and chlorobenzene. Where as for the other binary

mixtures, the –OH frequencies show some changes. In order to have an insight

into the nature of interaction between the components of liquid mixtures, the

change in IR frequencies of –OH group is calculated as,

IR frequencies of –OH group in the mixture – IR frequencies of –OH group

in the pure t-butanol.

It is seen that the values are negative for benzene, xylenes and aniline

while positive for nitrobenzene. It is concluded that there is variable degree of

intermolecular hydrogen bonding between the components of the mixtures.

It is interesting to note here that toluene and chloro substituted benzenes

do not show any changes in the frequencies of –OH group. It is also seen that the

Ar-Cl frequencies do not show any changes in chlorobenzene, o-chlorotoluene

and p-chlorotoluene.

179

In case of mixtures of t-butanol with toluene and xylenes sp3 (C-H)

frequencies show no changes with respective to the composition range. It is also

seen that these frequencies show almost an independent character with respect to

the position of the additional –CH3 group in xylenes ).

In case of mixture of t-butanol with nitrobenzene the symmetrical

(Ar-NO2) changes from 1348 in pure nitrobenzene to 1365 for 0.2

mole fraction of t-butanol but there after it shows no changes from the pure values

for t-butanol + Aniline, (N-H) symmetrical frequencies decreases from

3356 for pure aniline and the changes is maximum for 0.4 to 06. mole

fraction of t-butanol

180

REFERENCES

1) Pimemental G C, Mcclellan A L, Hydrogen Bond ; Freeman W H, San

Franciso, 1990.

2) Joseten M D, Schaad L, Hydrogen Bonding; Marcel Dekker, New York,

1974.

3) Vinogradav S N, Linnel R H, Hydrogen Bonding; Van Nostrand Reinhold,

New Yark,1971.

4) Legon A C, Millen D, J Chem Soc. Rev, 21 (1992) 71.

5) Scheiner S, Acc. Chem Res, 27 (1994) 402.

6) Etter M C, Acc. Chem Res, 23 (1990) 120.

7) Desirajau G R, Crystal Engineering: “The Design of Organic Solids”,

Elsevier Amsterdam (1989).

8) Jeffery G A, Saenger W, “Hydrogen Bonding in Biological Structures”,

Springer- Verlag Barlin, (1991).

9) Gerit J A, Kreevoy M M, Cleland W W, Frey P A, Chem Bio, 4 (1997) 259.

10) Kirby A J, Acc. Chem Res, 30 (1997) 290.

11) Wang B, Hinton J F, Polay P, J Phys Chem, 107 (2003) 4683.

12) Cubero E, Orozco M, Hobza P, Luque F, J Phys Chem, 103 (1999) 6394.

13) Hobza P, Havlas Z, Chem Phys Lett, 303 (1999) 447.

14) Scheiner S, Kr T, J Phys Chem, 106 (2002) 1784.

15) Silverstein R M, Webster F X “Spectrometric Identification of Organic

Compounds”, 6th

Ed, New York (2006).

16) Gunasekaran S, Natarajan R K, Rathika R, Syamala D, Indian J Pure

Appl Phys, 43 (2005) 509.

17) Gunasekaran S, Kumaresan S, Seshadri S, Muthu S, Indian J PureAppl

Phys, 46 (2008) 155.

18) Parimala S G, Indian J Chem 27A (1988) 947.

19) Mirti P, J Mol Liq, 38(1988) 215.

20) Singh K C, Kalra L C, Prashkumar, Indian J Chem, 29A(1990) 779.

21) Johnston K P, Meredith J, C Harrison K L, Fluid Phase Equilib,

116 (1996) 385.

22) Asahi N, Nakajmura Y, J Mol Liq, 90 (2001) 85.

23) Asprion N, Hasse H, Maurer G, Fluid Phase Equilib, 186 (2001) 1.

181

24) Brown K, Spectrochimica Acta Part A Mol Spectroscopy, 34 (1978) 117.

25) Dzwigaj S, Mallmann A, Barthomeuf D, J Chem Soc. Faraday Trans,

86 (1990) 431.

26) Scotoni M, Oss S, Lubich L, Furlani S, Bassi D, J Chem Phys,

103 (1995) 897.

27) Alejandre A G, Gonzalez H, Ramirez J, Ind Eng Chem Res,

40 (2001) 3484.

28) Wisniak J, Cortez G, Peralta R D, Infante R, Elizalde L E, J Solution Chem,

36 (2007) 997.

29) Grinvald I I, Domrachev G A, Kalagaev I Y, Doklady Phys Chem, 440

(2011) 168.

182

Table 5.1 : IR Frequencies ) for t-Butanol with Benzene

Mole fraction of t-Butanol

(O-H)

Benzene -

0.2 3360.11

0.4 3362.04

0.5 3354.32

0.6 3365.90

0.8 3348.54

t-Butanol 3377.47

183

Table 5.2 : IR Frequencies ) for t-Butanol with Chlorobenzene

Mole fraction of

t-Butanol

(O-H) (Ar-Cl)

Chlorobenzene - 740.69

0.2 3375.54 744.65

0.4 3381.33 742.62

0.5 3375.54 740.69

0.6 3383.26 740.69

0.8 3381.33 740.69

t-Butanol 3377.47 -

184

Table 5.3 : IR Frequencies ) for t-Butanol with Toluene

Mole fraction of t-Butanol

(O-H)

Toluene -

0.2 3379.51

0.4 3377.47

0.5 3379.40

0.6 3377.47

0.8 3383.26

t-Butanol 3377.47

185

Table 5.4 : IR Frequencies ) for t-Butanol with o-Chlorotoluene

Mole fraction of

t-Butanol

(O-H) (Ar-Cl)

o-Chlorotoluene - 746.81

0.2 3373.61 748.41

0.4 3377.47 748.41

0.5 3373.61 748.41

0.6 3373.47 748.41

0.8 3371.68 746.48

t-Butanol 3377.47 -

186

Table 5.5 : IR Frequencies ) for t-Butanol with p-Chlorotoluene

Mole fraction of

t-Butanol

(O-H) (Ar-Cl)

p-Chlorotoluene - 806.27

0.2 3379.40 806.27

0.4 3379.40 806.27

0.5 3379.40 806.27

0.6 3389.33 806.27

0.8 3367.82 806.27

t-Butanol 3377.47 -

187

Table 5.6 : IR Frequencies ) for t-Butanol with o-Xylene

Mole fraction of

t-Butanol

(O-H) (C-H) methyl

o-Xylene -

2970.48

2939.61

2920.32

0.2 3362.04

2970.48

2939.61

2920.32

0.4 3367.82

2972.40

2941.54

2875.96

0.5 3362.04

2972.40

2941.54

2875.96

0.6 3348.54

2972.40

2939.61

2875.96

0.8 3329.25

2970.48

2939.61

2920.32

t-Butanol 3377.47 -

188

Table 5.7 : IR Frequencies ) for t-Butanol with m-Xylene

Mole fraction of

t-Butanol

(O-H) (C-H) methyl

m-Xylene -

2920.32

2868.39

2731.29

0.2 3379.75

2972.40

2941.54

2874.03

0.4 3358.18

2972.40

2926.11

2872.10

0.5 3350.48

2972.40

2924.18

2872.10

0.6 3346.61

2972.40

2922.25

2870.17

0.8 3342.88

2970.48

2922.25

2866.32

t-Butanol 3377.47 -

189

Table 5.8 : IR Frequencies ) for t-Butanol with p-Xylene

Mole fraction of

t-Butanol

(O-H) (C-H) methyl

p-Xylene -

2933.83

2874.03

2966.62

0.2 3373.61

2972.40

2939.61

2875.96

0.4 3373.61

2972.40

2967.68

7875.96

0.5 3367.82

2972.40

2967.68

7875.96

0.6 3369.75

2972.40

2967.68

7875.96

0.8 3331.18

2968.55

2933.83

2874.03

t-Butanol 3377.47 -

190

Table 5.9 : IR Frequencies ) for t-Butanol with Nitrobenzene

Mole fraction of

t-Butanol

(O-H) (Ar- )

Nitrobenzene - Symm - 1348.29

Asymm - 1518.03

0.2 3377.47 Symm - 1365.65

Asymm - 1529.60

0.4 3381.33 Symm - 1348.29

Asymm - 1527.67

0.5 3396.76 Symm - 1348.29

Asymm - 1527.67

0.6 3417.98 Symm - 1348.29

Asymm - 1525.75

0.8 3574.21 Symm - 1348.29

Asymm - 1523.82

t-Butanol 3377.47 -

191

Table 5.10 : IR Frequencies ) for t-Butanol With Aniline

Mole fraction of

t-Butanol

(O-H) (N-H)

Aniline - Symm - 3356.25

Asymm - 3433.41

0.2 3375.54 Symm - 3337.99

Asymm - 3078.49

0.4 3360.11 Symm - 3037.99

Asymm - 3074.63

0.5 3358.18 Symm - 3037.99

Asymm - 3074.63

0.6 3356.25 Symm - 3037.99

Asymm - 3372.71

0.8 3356.25 Symm - 3336.06

Asymm - 3372.71

t-Butanol 3377.47 -

192

Figure 4.1 Neat FTIR -OH Frequency (cm-1

) Cut Section (Spectrum)

of t-Butanol

193

x1 = 0.4 x1 = 0.5 x1 = 0.6

Figure 4.2 : Neat FTIR -OH Frequency (cm-1

) Cut Section (Spectrum) of

t-Butanol + Benzene.

194

x1 = 0.4 x1 = 0.5 x1 = 0.6



t-Butanol + Chlorobenzene.

195

x1 = 0.4 x1 = 0.5 x1 = 0.6



t-Butanol + Toluene.

196

x1 = 0.4 x1 = 0.5 x1 = 0.6



t-Butanol + o-Chlorotoluene.

197

x1 = 0.4 x1 = 0.5 x1 = 0.6



t-Butanol + p-Chlorotoluene.

198

x1 = 0.4 x1 = 0.5 x1 = 0.6



t-Butanol + o-Xylene.

199

x1 = 0.4 x1 = 0.5 x1 = 0.6



t-Butanol + m-Xylene.

200

x1 = 0.4 x1 = 0.5 x1 = 0.6



t-Butanol + p-Xylene.

201

x1 = 0.4 x1 = 0.5 x1 = 0.6



t-Butanol + Nitrobenzene.

202

x1 = 0.4 x1 = 0.5 x1 = 0.6



t-Butanol + Aniline.

203

Figure 4.12 : Neat FTIR Ar-Cl Frequency (cm-1


Chlorobenzene.

204

x1 = 0.4 x1 = 0.5 x1 = 0.6

Figure 4.12 : Contd- Neat FTIR Ar-Cl Frequency ( cm-1

) Cut Section

(Spectrum) of t-Butanol + Chlorobenzene.

205



o-Chlorotoluene.

206

x1 = 0.4 x1 = 0.5 x1 = 0.6


) Cut Section

(Spectrum) of t-Butanol + o-Chlorotoluene.

207



p-Chlorotoluene.

208

x1 = 0.4 x1 = 0.5 x1 = 0.6


) Cut Section

(Spectrum) of t-Butanol + p-Chlorotoluene.

209

Figure 4.15 : Neat FTIR Sp3 C-H Frequency (cm

-1) Cut Section (Spectrum)

of o-Xylene.

210

x1 = 0.4 x1 = 0.5 x1 = 0.6

Figure 4.15 : Contd- Neat FTIR SP3 C-H Frequency (cm

-1) Cut Section

(Spectrum) of t-Butanol + o-Xylene

211



of m-Xylene

212

x1 = 0.4 x1 = 0.5 x1 = 0.6

Figure 4.16 : Contd- Neat FTIR Sp3 C-H Frequency (cm

-1) Cut Section

(Spectrum) of t-Butanol + m-Xylene

213



of p-Xylene

214

x1 = 0.4 x1 = 0.5 x1 = 0.6

Figure 4.17 : Contd- Neat FTIR Sp3 C-H Frequency (cm

-1) Cut Section

(Spectrum) of t-Butanol + p-Xylene

215

Figure 4.18 : Neat FTIR Ar-NO2 Frequency (cm-1


of Nitrobenzene

216

x1 = 0.2 x1 = 0.4 x1 = 0.5

Figure 4.18 : Contd- Neat FTIR Ar-NO2 Frequency ( cm-1

) Cut Section

(Spectrum) of t-Butanol + Nitrobenzene.

217

Figure 4.19 : Neat FTIR N-H Frequency (cm-1


of Aniline

218

x1 = 0.4 x1 = 0.5 x1 = 0.6

Figure 4.19 : Contd- Neat FTIR N-H Frequency (cm-1


of t-Butanol + Aniline

chapter - 5 infrared spectroscopic studies of binary...

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