Dielectric technique under 9.36 GHz electric field. The increasing

Dielectric Relaxation Phenomena of Aniline and
Substituted Anilines with Acetonitrile under 9.36 GHz Electric Field.

Soumya
Sundar Pattanayak

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

Department
of Electronics &

Instrumentation
Engineering

National
Institute of Technology Silchar

Silchar,
Assam, India 788010

[email protected]

 

Tushar
Bachhar

Department
of Electronics &

 Instrumentation Engineering

National
Institute of Technology Silchar

Silchar,
Assam, India 788010

[email protected]

Swagatadeb
Sahoo

Department
of Electronics &

Instrumentation
Engineering

National
Institute of Technology Silchar

Silchar,
Assam, India 788010

[email protected]

 

Abstract— Relaxation times and  due to whole molecular rotation and the
flexible parts of the dilute binary (jk) polar solution of three amine(j) and
acetonitrile(k) in C6H6 (i) at 30ºC are estimated using
susceptibility measurement technique under 9.36 GHz electric field. The
increasing values of ? signify the
increasing acidity of amine (proton donor) in complex systems. But in nitriles with N, N-dimethyl amine systems,
the ? values are less than the other amine complexes due to steric hindrance
and inductive effect.  . The measured relaxation
time (?’s) and dipole moment (µ’s) match well with the reported values
establishing the utility of the proposed method. Solute-solvent and
solute-solute molecular associations are ascertained in various molecular
environments due to different electron affinity of adjacent atoms. Thermodynamic
energy parameters are calculated using Eyring rate theory to predict the
molecular dynamics of the system.

 

     
Index Terms— Dielectric relaxation, relaxation time, dipole moment,
solute-solvent association.

I. 
Introduction

Dielectric
spectroscopy is an old experimental tool which has dramatically developed in
last three decades 1-3. As a simple, rapid and non-destructive measuring
technique, dielectric spectroscopy provides information about dielectric
response of material to electromagnetic field and enables researchers to make
sound contribution to contemporary problems in modern science and engineering. Amines have attracted the
attention of a large number of research workers 4, 5 because of their high
dielectric constant and wide biological applications. In automobile and
construction industries, aniline is extensively used. Various chemicals including
Isocyanaates for the urethane industry, antioxidants,
activators, accelerators, dyes and pigments are produced from aniline. Now a
days, N-methylaniline is the best alternative of traditional anti knock agent
and widely used in petroleum industries. It is also used as an intermediate for
dyes, agrochemicals and other organic products. On the other hand,
acrylonitrile is used as a solvent for the production of pharmaceuticals and
photographic film. Because of its inherent high dielectric constant,
acrylonitrile is widely used in battery industries. Dielectric relaxation studies of polar
solutes in non-polar solvent using microwave absorption technique are expected
to throw much light on various type of molecular association because of the capacity
of microwaves to detect weak molecular association 6, 7. In our study, we
have made thorough investigation on polar mixture of amines and acetonitrile
dissolved in non-polar solvent C6H6, in terms of measured
real ?ijk¢  and imaginary ?ijk¢¢ parts of high frequency complex  susceptibility ?ijk*at temperature 300C and weight
fractions wjk’s  of  polar solutes at 9.36 GHz electric field. The susceptibility measurement technique is related
to orientational polarization unlike permittivity Îijk’s and conductivity ?ijk’s concerned with all types of
polarization and bound molecular charge of the polar molecules respectively. Recently,
susceptibility method 8 under microwave electric field is well accepted for binary
polar mixture dissolved in nonpolar solvents. However, no such extensive
investigation has been made so far on aniline and substituted anilines with
acetonitrile dissolved in C6H6 at 300C
temperature under microwave field using susceptibility measurement technique.
The aim of susceptibility measurement technique is to correlate dielectric
relaxation study with structure as well as dynamics of the liquid mixture
described by other technique 9. The purpose of this paper is to establish the
applicability of susceptibility measurement method within the frame work of
Debye model for liquid mixture at microwave field like earlier 8.

 

II.EXPERIMENTAL PROCEDURE

All
the polar and non-polar materials are AR grade and used directly in the
experiment. Different weight fractions of polar mixtures of aniline, N-methyl
aniline, N, N-dimethyl aniline with acetonitrile dissolved in non-polar solvent
C6H6 are prepared using micro pipet and a magnetic
stirrer to make dilute solutions. Five different weight fractions of each
polar-non polar mixture where studied with help of a Network Analyzer assembly
using high temperature dielectric probe