Indian Journal of Pure & Applied Physics
Vol. 50, March 2012, pp. 175-183
Dielectric behaviour of aprotic polar liquid dissolved in non-polar solvent under
static and high frequency electric field
S Sahoo1*, T R Middya2 & S K Sit3
1
Department of Electronics & Instrumentation Engineering, 3Department of Physics
Dr. Meghnad Saha Institute of Technology, P O Debhog, Haldia, Dist Purba Medinipore, West Bengal, India, 721657
2
Department of Physics, Jadavpur University, Kolkata, West Bengal, India
3
E -mail : swapansit @ yahoo. co.in
Received 29 November 2011; revised 4 January 2012; accepted 11 January 2012
Dielectric behaviour of aprotic polar liquids (j) like N,N dimethylformamide (DMF), N,N dimethylacetamide (DMA)
and acetone (Ac) has been studied under static as well as 9.987, 9.88 and 9.174 GHz electric field employing Debye theory
of polar-non polar liquid mixture in terms of measured İ′ij and imaginary İ″ij part of complex relative permittivity İij*, static
0ij and high frequency İij for different wj’s of solute dissolved in non polar solvent at 27°C temperature. Double relaxation
times 2 and 1 due to whole molecule and part of the polar molecule have also been estimated analytically using the
complex high frequency orientational susceptibility Ȥij* (= İij*−İij) from measured data for DMF and DMA in C6H6 and
CCl4 as well as acetone in C6H6 and CCl4 solvent, respectively at 27°C. Out of the six systems, three systems show double
relaxation time 2 and 1 and dipole moment 2 and 1. The estimated ’s and IJ’s agree excellently well with the reported
and measured values from ratio of slope and linear slope method. The dipole moments 0s’s in static electric field are also
compared with ȝj’s in hf method. The relative contributions c1 and c2 due to IJ1 and 2 have been calculated from Fröhlich
equation as well as graphical plot of χ′ij/χ0ij −wj and ″ij/0ij −wj curve at wj0. Solute-solute and solute-solvent molecular
associations are ascertained in different molecular environment.
Keywords: Double relaxation times, Dipole moment, Monomer, Dimer
1 Introduction
Amides have attracted the attention of a large
number of researchers1-4 because of their high
dielectric constant and wide biological applications.
Amides are pervasive in nature and technology as
structural materials. The amide linkage is easily
formed which confers structural rigidity and resists
hydrolysis. Moreover, amide linkages constitute a
defining molecular feature of proteins. The secondary
structure is a part to the hydrogen bonding abilities of
amides. N,N-dimethylformamide (DMF), N,N-dimethyl
acetamide (DMA) are recognized as non-aqueous
dipolar aprotic solvent. Acetone (Ac) on the other
hands is a good aprotic solvent for the manufacturer
of smokeless powder and used as raw materials for
the production of idoform and chloroform. Dielectric
relaxation studies of polar solutes in non-polar solvent
using microwave absorption technique are expected to
throw some light on various type of molecular
association because of the capacity of microwaves to
detect weak molecular association5-7. Dhull and
Sharma8,9 measured dielectric constant (İ′ij), dielectric
loss (İ″ij) of dilute solution of N,N-dimethyl-
formamide (DMF), N,N-dimethylacetamide (DMA)
in benzene, dioxane and carbon tetrachloride using
standing wave technique at 25,35,45,55°C under
9.987 GHz electric field to calculate dielectric
relaxation time (), dipole moment (ȝ), energy
parameters (F, H, S) at various temperatures
and weight fractions of solutes dissolved in non- polar
solvents from their measured data. They proposed for
monomer and dimmer association in various solvent
in terms of measured IJ and ȝ. They compared the
evaluated energy parameters with corresponding
viscosity parameters to show that the dielectric
relaxation process like viscous flow can be considered
as a rate process.
The existence of double relaxation phenomenon of
DMF, DMA and Ac dissolved in benzene or carbon
tetrachloride has been studied at 27°C for different
wj’s of solutes in terms of measured real ′ij (İ′ij−İij)
and imaginary ″ij (İ″ij) parts of high frequency
orientational susceptibility ij* (İij−İij) and 0ij (İ0ij −
İij) which is real from single frequency susceptibility
measurement technique10. This study offers to get the
double relaxation times 2 and 1 due to rotation of the
176
INDIAN J PURE & APPL PHYS, VOL 50, MARCH 2012
whole and flexible part of the polar molecules under
high frequency electric field as well as dipole moment
2 and 1 to enable one to get information on intra and
intermolecular interactions and their structures. To
calculate IJ2, IJ1 and ȝ2, ȝ1 accurate measurement of İ0ij
and İij are needed. The static dipole moments ȝ0s’s
under static and low frequency electric field were
estimated in terms of slope a1 of static experimental
parameter Xij[={(ε0ij−ε∞ij)}/{(ε0ij+2)(ε∞ij+2)}] against wj
within the frame work of Debye model of polar-non
polar liquid mixture.
Aprotic polar solute (j) dissolved in benzene is
usually showed11 double and single relaxation
mechanism under ~ 10 GHz electric field. The
purpose of the present paper is to study the occurrence
of double relaxation mechanism of six systems at
27°C temperature and different wj’s of solutes using
susceptibility measurement technique and thereby to
predict structure, shape, size of polar molecule and
various molecular association like solute-solvent
(monomer) and solute-solute (dimer). It is worthwhile
to investigate how far measured relaxation times IJ2
and IJ1 and dipole moment 2 and ȝ1 agree with
reported IJ’s and ȝ’s from Gopalakrishna’s method as
well as static 0s and to see whether a part of the
molecule or whole molecule is rotating under high
frequency electric field within the frame work of
Debye model of polar-non polar liquid mixture.
2 Experimental Details
The aprotic polar liquids DMF, DMA and Ac
(E.Merck) and the solvents C6H6 and CCl4 were used
after distillation. The solutions of different
concentrations were made by mixing a certain weight
of solute with solvent using electronic balance and
micro pipet. Agilent E4980A precision LCR meter
has been used to measure 0ij and İij of six systems
under investigation. The frequency range of LCR
meter is 49 Hz to 5 MHz. The values of İ′ij and İ″ij for
a given wj’s of solutes under different frequency of
MHz range have been carefully measured to draw the
Cole-Cole semicircular arc plot to get accurate values
of İ0ij and İij. The values of İ′ij and İij are, however,
extracted from the measured data8,9 at the desired
concentration using least squares fitting procedure.
All the measured data are presented in Table 1.
3 Theory
3.1 Static dipole moment µ0s
The static dipole moment µ0s of a polar solute (j)
dissolved in solvent (i) under static or low frequency
electric field at temperature T, K within the frame
work of Debye model8 is given by:
ε0ij −1 ε∞ij −1 ε0i −1 ε∞i −1 N µ02s c j
−
=
−
+
ε0ij + 2 ε∞ij + 2 ε0i + 2 ε∞i + 2 9ε0 KBT
…(1)
where ε0 is the absolute permittivity of free space =
8.854×10−12 Fm−1.
The molar concentration cj of the polar solute can
be expressed in terms of weight fractions wj’s of polar
solute as:
cj =
ρij w j
…(2)
Mj
Again, the density ij of the binary solution is written
as :
ρij = ρi (1 − γ w j )−1
…(3)
Eq. (1) can now be written as :
ε 0ij − ε ∞ij
ε 0 i − ε ∞i
=
(ε 0ij + 2)(ε ∞ij + 2) (ε 0i + 2)(ε ∞i + 2)
+
X ij = X i +
N ρi µ s2
w j (1 − γ w j ) −1
27ε 0 M j k BT
N ρi µ s2
N ρi µ s2
wj +
γ w2j
27ε 0 M j k BT
27ε 0 M j k BT
…(4)
Eq. (4) is a polynomial equation of Xij against wj.
On differentiation of Eq. (4) with respect to wj and at
wj →0 one gets:
ª 27ε 0 M j k BTa1 º
µ0 s = «
»
N ρi
¬
¼
1/ 2
…(5)
where a1 is the slope of Xij −wj curve at wj →0. The
curves of Xij−wj are shown in Fig. 1. Mj being the
molecular weight of polar solute. All other symbols
are expressed in SI units13.
3.2 Double relaxation times τ2 and τ1 and relative
contributions c1 and c2
Bergmann et al15. suggested a graphical method to
get τ1 and τ2 of a polar liquid mixture dissolved in
benzene (i) in terms of measured χ′ij, χ″ij and χ0ij
under different frequency of GHZ electric field and
temperature T, K as:
χ ij'
c1
c2
=
+
2 2
χ 0ij 1 + ω τ 1 1 + ω 2τ 22
…(6)
SAHOO et al.: DIELECTRIC BEHAVIOUR OF APROTIC POLAR LIQUID
177
INDIAN J PURE & APPL PHYS, VOL 50, MARCH 2012
178
0.03
ij
X
(VI)
(II)
0.02
(IV)
(I)
0.01
(III)
(V)
0.002
0.004
0.006
0.008
0.010
0.012
wj
Fig. 1 — Variations of static experimental parameter Xij against
weight fractions wj’s of different polar solutes dissolved in non
polar solvent under static electric field at 27 ° C temperature.(I)
— — for DMF+C6H6 (II) — — for DMF+CCl4 (III) —
— for DMA+ C6H6 (IV) —  — for, DMA+ CCl4, (V) —
— for Ac+ C6H6 (VI) — — for Ac+ CCl4,respectively
χ ij"
ωτ 1
ωτ 2
= c1
+ c2
2 2
χ 0ij
1 + ω τ1
1 + ω 2τ 22
…(7)
where c1, c2 are the relative contributions due to two
broad Debye type dispersions such that c1 + c2 = 1.
Eqs (6) and (7) are solved for c1 and c2 to get a
straight line equation as :
χ 0ij − χ ij'
χ ij"
= ω (τ 2 + τ 1 ) ' − ω 2τ 1τ 2
'
χ ij
χij
…(8)
where ω (τ 2 + τ 1 ) and − ω 2τ 1τ 2 are the slopes and
intercepts of Eq. (8) obtained by least squares fitting
procedures of variables (χ0ij−χ′ij)/χ′ij plotted against
χ″ij / χ′ij for different wj’s under a given angular
frequency ω(=2πf). The intercepts and slopes are
justified up to four decimal place along with τ’s from
double relaxation phenomenon, are presented in
Table 2.
τ’s were also calculated from the linear slope of χ″ij
against χ′ij of Fig. 2 as suggested by Murthy et al15.
d χ ij"
d χ ij'
= ωτ
…(9)
Both χ″ij and χ′ij are the functions of wj’s. To avoid
polar-polar interactions one could use the ratio of
slopes of χ″ij −wj and χ′ij − wj curves at wj →0 to
measure τ as shown in Figs 3 and 4.
SAHOO et al.: DIELECTRIC BEHAVIOUR OF APROTIC POLAR LIQUID
0.6
(II)
0.15
179
(VI)
(II)
(VI)
0.4
(IV)
0.10
(IV)
χij
''
χij
'
(III)
(I)
0.05
(V)
0.2
(III)
(V)
0.00
(I)
0.0
0.005
0.0
0.2
0.4
χij
Fig. 2 — Straight line plot of ij against ij of different polar
solutes in non polar solvent at 27°C temperature under ∼10 GHz
electric field. (I) — — for DMF+C6H6 (II) — — for
DMF+CCl4 (III) — — for DMA+ C6H6 (IV) —  — for
DMA+ CCl4, (V) — — for Ac+ C6H6 (VI) — — for Ac+
CCl4,respectively
(VI)
(II)
χij
''
0.10
§ χij'
χ" ·
α 2 − ij ¸¸ (1 + α12 )
¨¨
χ 0ij
χ 0ij ¹
c1 = ©
α 2 − α1
(III)
(V)
0.00
0.004
0.006
0.008
0.010
0.012
wj
Fig. 3 — The plot of ij against weight fractions wj’s of different
polar liquids in non polar solvents at 27°C temperature under
∼10 GHz electric field. (I) — — for DMF+C6H6 (II) — —
for DMF+CCl4 (III) — — for DMA+ C6H6 (IV) —  — for
DMA+ CCl4, (V) — — for Ac+ C6H6 (VI) — — for
Ac+ CCl4, respectively
§ d χ ij"
¨¨
© dw j
·
¸¸
¹ w j →0
§ d χ ij'
¨¨
© dw j
·
¸¸
¹ w j →0
All the τ’s including the most probable τ 0 = τ1τ 2 ,
(I)
0.05
0.002
Fig. 4 — Variation of χ′ij against weight fractions wi’s of different
polar solutes in non- polar solvent at 27°C temperature under ∼10
GHz
electric
field.
(I)
——
for
DMF+C6H6
(II) — — for DMF+CCl4 (III) — — for DMA+ C6H6
(IV) —  — for, DMA+ CCl4, (V) — — for Ac+ C6H6 (VI)
— — for Ac+ CCl4 respectively.
reported τ due to Gopalakrishna’s method,
symmetrical τs and characteristics τcs are placed in
Table 2. The values of τ’s are significant up to two
decimal place.
A continuous distribution of τ’s between two
extreme values of τ2 and τ1 for three systems inspires
one to calculate c1 and c2 from Eqs (6) and (7) as
follows :
0.15
(IV)
0.020
wj
0.6
'
0.015
0.010
= ωτ
…(10)
§ χ" χ '
·
¨ ij − ij α1 ¸ (1 + α 22 )
¨ χ 0ij χ 0ij ¸
¹
c2 = ©
α 2 − α1
…(11)
…(12)
where α1 = ωτ 1 and α 2 = ωτ 2 such that α 2 > α1 .
The experimental c1 and c2 were calculated from the
parabolic fitted curve of χ″ij /χ0ij and χ′ij /χ0ij against
wj at wj →0 as shown in Fig. 5. The theoretical c1 and
c2 were also calculated in terms of χ′ij /χ0ij and χ″ij/χ0ij
following Fröhlich’s equations17 as:
χ ij'
1 ª1 + ω 2τ 22 º
=1−
ln «
»
χ 0ij
2 A ¬1 + ω 2τ 12 ¼
…(13)
INDIAN J PURE & APPL PHYS, VOL 50, MARCH 2012
180
(I)
ª
1«
τs =
1
ω«
«¬
0.36
(III)
0.90
(II)
0.34
''
χij /χ0ij
χij /χ0ij
0.88
where
'
0.32
1
­§ χ ' ·
°¨ ij ¸
§ γπ ·
§ γπ
® " cos ¨ ¸ − sin ¨
© 2 ¹
© 2
°¯¨© χ ij ¸¹
½º 1−γ
·°»
¸ ¾»
¹°
¿»¼
…(18)
χij'
χij"
and
are obtained from Fig. 5 at
χ 0ij
χ 0ij
wj → 0 .
0.86
(III)
(II)
0.30
On simplification of Eq. (16) further, one gets:
(I)
0.002
0.004
0.006
0.008
0.010
1
0.012
φ
wj
Fig. 5 — Variations of χ′ij / χ0ij and χ″ij / χ0ij against weight
fraction wj of DMF and DMA at 27°C temperature under
9.987 GHz electric field (I) — — and … … for DMF+CCl4
(II) — — and … … for DMA+ C6H6 (III) — — and
…… for DMA+ CCl4 respectively
χ ij" 1
= ª tan −1 (ωτ 2 ) − tan −1 (ωτ 1 ) º¼
χ 0ij A ¬
…(14)
where A= Fröhlich’s parameter = ln ( τ 2 / τ 1 ).
3.3 Symmetric and asymmetric distribution parameter γ and į
The three systems i.e DMF in CCl4, DMA in C6H6
and DMA in CCl4 for different wj’s of solute
exhibiting molecular non-rigidity are expected to
show symmetric or asymmetric distribution of
relaxation parameters as:
χ ij*
1
=
χ 0ij (1 + jωτ cs )δ
…(16)
ª§
χij'
tan −1 «¨1 −
«¨ χ 0ij
π
©
ij
ij
0 ij
…(19)
…(20)
0 ij
where tan φ = ωτ cs .
Measured parameter of [log{( χ′ij/ χ0ij)/cos(φδ)}]/φδ
of Eqs (19) and (20) are estimated and the value of
φ is ascertained from the theoretical curve of
1/φ log(cosφ) against φ 11. į can also be found out
from the known φ of Eq. (20).
3.4 Dipole moments µjk from susceptibility measurement
technique
The imaginary part of dielectric orientational
susceptibility χ″ij as a function of wj of a binary polar
mixture can be written as10 :
§ ωτ j ·
2
ε ij + 2 ) w j
¨¨
(
2 2 ¸
¸
27ε 0 M j K BT © 1 + ω τ j ¹
N ρij µ 2j
…(21)
On differentiation of Eq. (21) w.r. to wj and at
infinite dilution i.e wj0 yields:
where γ= symmetric and δ = asymmetric distribution
parameters related to symmetric τs and characteristic
relaxation times τcs, respectively.
Eq. (15), on simplification of real and imaginary
parts yields :
2
χ" χ )
(
tan (φδ ) =
(χ' χ )
χ =
…(15)
) cos (φδ )º»¼
(φδ )
"
ij
χ ij*
1
=
χ 0ij 1 + ( jωτ s )1−γ
γ=
(
log ª χ ij' χ 0ij
«¬
log(cos φ ) =
· χ ' χ" º
¸ ij − ij »
¸ χ " χ 0ij »
¹ ij
¼
…(17)
§ d χ ij"
¨¨
© dw j
·
N ρi µ 2j
=
¸¸
¹ w j →0 27ε 0 M j K BT
§ ωτ j ·
2
(ε i + 2 )
¨¨
2 2 ¸
¸
© 1+ ω τ j ¹
…(22)
where µj is the dipole moment of polar solute of
molecular weight Mj; The other symbols carry usual
meaning in SI unit as mentioned elsewhere10.
On comparison of Eqs (10) and (22), one gets:
§ d χ ij'
¨¨
© dw j
·
·
N ρi µ 2j §
1
2
=
( ε i + 2 ) …(23)
¸¸
¨¨
2 2 ¸
¸
¹ w j →0 27ε 0 M j K BT © 1 + ω τ j ¹
SAHOO et al.: DIELECTRIC BEHAVIOUR OF APROTIC POLAR LIQUID
Eq. (23) yields dipole moment µj as:
1
ª 27ε 0 M j K BT β º 2
µj = «
2 »
«¬ N ρi ( ε i + 2 ) b »¼
...(24)
where β (significant up to four decimel place) is the
slope of χ′ij−wj curve at wj0 and b is a
dimensionless parameter. They are placed in Table 3.
All the µ’s justified up to two decimal place along
with theoretical and experimental contributions c1 and
c2 are placed in Table 3.
4 Results and Discussion
The measured İ′ij, ij″, İ0ij and ij for different wj’s
of solute are given in Table 1. The concentration of
the polar solute for each dilute solution of polar-non
polar liquid mixture are made extremely low. In that
case, one polar unit is sufficiently apart from the other
so that a polar unit may be considered as quasiisolated validating the applicability of Debye theory
for polar molecule.
The static dipole moment 0s’s are estimated from
the slope of Xij−wj curve of Fig. 1. The ȝ0s’s thus
estimated are placed in Table 1 along with slope a1 of
Xij−wj curve, reported and estimated ’s as well as
theoretical ȝ theo’s. As evident from Fig. 1 that
polarization increases gradually with the rise of wj’s
of solute under static field. Similar nature of
curve(III) and (V) exhibiting almost same slope and
intercepts may be due to their same polarity as
observed15.The system DMA in CCl4 (II), however,
shows maximum polarization in comparison to other
system. This is probably due to solute-solute (dimer)
molecular association at higher concentration region.
At infinite dilution i.e wj→0, the same polar molecule
in different non- polar solvents environment yields
different polarization probably due to solvent effect18.
The estimated values of 0s’s are agree excellently
well with the reported ’s of Gopalakrishna’s
method19 in the high frequency electric field
signifying the fact that the frequency of the electric
field affects a little in determining ’s as observed7. It
is evident from Table 2 that three systems out of six
systems exihibit double relaxation times 2 and 1. The
values of ’s from linear slope of ȤijƎ− Ȥij' curve of
Fig. 2 following the procedure of Murthy et al 13.
agree excellently well and placed in Table 2. The
values of ’s have also been calculated from the ratio
of slopes of Ȥij−wj and Ȥij−wj curves of Eq. (10) and
181
INDIAN J PURE & APPL PHYS, VOL 50, MARCH 2012
182
(i)
CH
3
7.02 O 1.45
C.m C.m δ
C0.31 N
CH3
1.45C.m
0.68
C.m C.mδ
1.08C.m
H
(ii)
9.09
C.m
O
.m
3C
8.5
1.87CH3
1.87C.m
C.m
H 0.88C 1.32
N
8.47
C.m
2.31C.m
.
10.96
.2C
11
C.m
m
CH3
C.m C.m
Cl
C
Cl Cl
Cl
(iii)
(iv)
O
CH
O
CH
3.5C.m
.
2C
9.6
m
7.43 1.53 3
C.m C.m δ
H3 C
C N CH3
0.89 1.08 1.53C.m
C.m C.m δ
8.96
C.m
4.86C.m
m
C. 12.46
.37
13
C.m
10.33 2.13 3
C.m C.m
H3C 1.23 C 1.5 N CH3
2.31C.m
C.m C.m
Cl
C
Cl Cl
Cl
(v)
H3C
4.03
C.m
0.48
C.m
O
C
0.48
C.m
4.03C.m
CH3
O
(vi)
H3 C
9.09
C.m
C
1.08 1.08 CH3
C.m Cl C.m
9.09
C.m
C
Cl Cl
Cl
CH3
δ
O
(vii)
H
N
C
CH3
δ
O
H
C
O
(viii)
H
CH3
δ
N
C
H
CH3
CH3
δ
N
CH3
δ
O
CH3
C
N
CH3
O
(ix)
H3C
C
δ
O
H3 C
C
CH3
δ
CH3
Fig. 6 — Theoretical dipole moments µtheo’s from available bond
angles and bond moments (multiples of 10-30 cm) along with
solute-solvent and solute-solute molecular associations (i) DMFC6H6, (ii) DMF+CCl4, (iii) DMA+ C6H6, (iv) DMA+ CCl4, (v)
Ac+ C6H6, (vi) Ac+ CCl4, (vii) DMF-DMF, (viii) DMA-DMA,
(ix) Ac-Ac
are shown in Figs 3 and 4, respectively. All the values
of Fig. 3 are found to increase with wj’s under high
frequency electric field. This type of nature indicates
the absorption of electric energy with the increase of
solute concentration. The absorption is the maximum
for DMF in CCl4 (II) and minimum for Ac in
CCl4(V). Fig. 4 shows the convex nature of all the
curves indicating the highest asymmetric nature of the
polar molecule at wj≅0.015 probably due to solutesolute molecular association of the polar liquids.
Table 2, however, presents that IJ1’s of three systems
and 2’s of three systems exhibiting mono-relaxation
behaviour which agree well with the reported and
measured values. Most probable τ 0 = τ1τ 2 ,
symmetric IJs and characteristic IJcs are also estimated
and placed in Table 2 along with symmetric
distribution parameters γ and asymmetric distribution
parameters for comparison. This fact signifies that
double
relaxation
phenomena
offer
better
understanding of relaxation behaviour of polar solutes
in non- polar solvents by yielding microscopic as well
as macroscopic relaxation8.
The dipole moments µ2 and µ1 due to 2 and 1 in
terms of slope β of χ′ij−wj curve (Fig. 4) and
dimensionless parameter b are estimated and placed in
Table 3. They are compared with the measured µ’s
from ratio of slopes as well as linear slope method. In
all the cases,the agreement is better signifying the
validity of the method adopted here. The relative
contributions c1 and c2 due to τ1 and τ2 are also
estimated from Fr Ö hlich’s Eqs (13) and (14) as well
as graphical plots of χ′ij/χ0ij and χ″ij/χ0ij against wj of
wj→0 of Fig. 5. In both the cases, c1+ c2 ≅1 as evident
from Table 3. Table 3 also presents that measured and
reported values of µ’s agree well with the estimated
values of µ1’s of three systems and µ2’s of other three
systems showing single relaxation behaviour. This
fact reveals that a part of the molecule is rotating
under high frequency electric field10,11. The theoretical
dipole moments theo’s of the polar molecules are
ascertained the available bond angles and bond
moments of 2.13×10-30 cm, 1.5×10−30 cm, 10-30 cm,
1.23×10−30 cm, 10.33×10-30 cm of N←CH3, C←N,
C←H, CH3←C, and C⇐O substituent polar groups as
shown in Fig. 6. It is evident from Table 3 that
estimated values of µ’s are slightly greater in solvent
CCl4 than C6H6. This is probably due to the solutesolvent association of polar molecules with CCl4
attributed by the interaction of dipolar solute with a
C-Cl dipole whose local field is not cancelled by other
SAHOO et al.: DIELECTRIC BEHAVIOUR OF APROTIC POLAR LIQUID
dipoles. In solvent C6H6 too, interaction of the
fractional +ve charge on N-atom of amides or C atom
in acetone with the π delocalized electron cloud of
benzene ring may be responsible for solute-solvent
association.
5 Conclusions
The simple Debye model of polar-non polar liquid
mixture, thus, satisfactorily explains the dielectric
behaviour of amides and acetone under static and high
frequency electric field in terms of measured
relaxation parameter İij’s and ij’s. Double relaxation
phenomenon of aprotic polar liquid is predicted for
DMA in C6H6 and CCl4 as well as DMF in CCl4
alone. Estimated values of µ2 and µ1 are compared
with the static 0s under low frequency field as well as
measured and reported µ’s in GHz range. This
agreement is good signifying the validity of the
method. Solute-solute (dimmer) and solute-solven
(monomer) molecular associations are ascertained in
different solvent environment.
References
Kumlar W D & Porter C W, J Am Chem Soc, 56 (1934)
2549.
2 Rabinovitz M & Pines A, J Am Chem Soc, 91 (1969)
1585.
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
1
18
19
183
Jain Ritu, Bhargava Nidhi, Sharma K S & Bhatnagar D,
Indian J Pure & Appl Phys, 49 (2011)401.
Kumar Raman, Kumar Chaudhury Raman & Rangra V S,
Indian J Pure & Appl Phys, 49 (2011)42.
Kumar Sandeep, Sharma D R, Thakur N, Rangra V S & Negi
N, Z Phys’ Che,iz, 219 (2005) 1431.
Kumar Raman, Kumar Raman & Rangra V S, Z Naturforsch,
65a (2010) 141.
Kumar Raman, Kumar Vinod & Rangra V S, Indian J Pure
& Appl Phys, 48 (2010)415.
Dhull J S & Sharma D R, J Phys:D, 15 (1982) 2307.
Dhull J S & Sharma D R, Indian J Pure & Appl Phys, 21
(1983) 694.
Sahoo S & Sit S K, Material Science & Engg B, 163 (2009)
31.
Sit S K, Dutta K, Acharyya S, Pal Majumder T & Roy S,
J Mol Liquid, 89 (2000) 111.
Sahoo S, Dutta K, Acharyya S & Sit S K, Indian J Pure &
Appl Phys, 45 (2007)529.
Sahoo S & Sit S K, Pramana Journal of Phys, 77, No 2
(2011) 395.
Jonscher A K, Physics of dielectric solids, invited paper
edited by CHL Goodman
Bergmann K, Roberti D M & Smyth C P, J Phys Chem, 64
(1960) 665.
Murthy M B R, Patil R L & Deshpande D K, Indian J Phys,
63B (1989) 491.
Fr Ö hlich H, Theory of Dielectrics, Oxford University Press,
Oxford (1949).
Chatterjee A K, Saha U, Nandi N, Basak R C & Acharyya S,
Indian J Phys, 66B (1992) 291.
Gopalakrishna K V, Trans Faraday Soc, 33 (1957) 767.