Phase Transitions and Thermodynamic Parameters of N-(p-n-octyloxybenzylidene)-p-n-alkoxyanilines—A Dilatometric Study

Abstract

The variation of density with temperature in four compounds, N-(p-n-octyloxybenzylidene)-p-n-alkylanilines, 8O.Om's, viz. N-(p-n-octyloxybenzylidene)-p-n-propoxyaniline, 8O.O3, N-(p-n-octyloxybenzylidene)-p-n-butylaniline, 8O.O4, N-(p-n-octyloxybenzylidene)-p-n-hexylaniline, 8O.O6, and N-(p-n-octyloxybenzylidene)-p-n-heptylaniline, 8O.O7, is presented. The density and thermal expansion coefficient results reveal that the phase transitions present in these compounds are of first order. Using the thermal expansion coefficient, the temperature dependence of a number of thermodynamical (thermoacoustic and anharmonic) parameters of these compounds are estimated. These results reveal that all the parameters show characteristic change in the vicinity of the phase transformation. The results are discussed in light of the body of data available.

Keywords:

• nO.Om compounds
• phase transitions
• thermodynamic parameters

Acknowledgments

K. Fakruddin and R. Jeevan Kumar are grateful to the head of the Department of Physics, S. K. University, for providing facilities to carry out this work. Dr. V. G. K. M. Pisipati, D. Madhavi Latha, and B. T. P. Madhav express their thanks to the head of the ECE Department and the management of K. L. University, Vaddeswaram, India, for providing financial assistance and Dr. P. V. Datta Prasad expresses his deep appreciation to the management of the the Hindu College, Machilipatnam, India, for providing computational facilities.

Notes

1. Ajeetha, N. Ramakrishna, M. Datta Prasad, P.V., & Pisipati, V.G.K.M., (2006). Mol. Cryst. Liq. Cryst., 452, 3.