Determination of the dipole moment of polar compounds in nonpolar

Michel Sliwa, Sylvie Létard, Isabelle Malfant, Martine Nierlich, Pascal G. Lacroix, Tsuyoshi Asahi, Hiroshi Masuhara, Pei Yu, and Keitaro Nakatani. C...
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Determination of the Dipole Moment of Polar Compounds in Nonpolar Solvents G e o r g e M. Janini a n d Ali H. Katrib Kuwait University, Kuwait Dipole moments can give valuable information about the ohvsical structure of molecules. Most exoerimental . . chemistm handbooks descrihe experiments for the determination of the electric dipole moment of polar solutes in nonpolar solvents, h u t their procedures are unnecessarily complicated. We orooose a simole exoeriment hased on the orocedure of ~ u & e n h e i m( 1 ) and ~ m ' i t h(2) for the determination of the d i o d e moments of the isomeric comoounds. D-methoxvbenzGlidene-p-cyanoaniline and p-cyanobenzylidene-pmethoxyaniline. Although similar in chemical structure, size, and shape, the two compounds have different dipole moments. T h e difference is readily explained us in^ simple resonance structures that are already familiar to the itudents from basic organic chemistry courses. The experiment descrihed herehas heen used successfully a t Kuwait University in a physical chemistry laboratory. I t requires not more than a three-hour period.

Table 1. Dielectric Constants and Refractive Indices of Solutions In Benzene at 25'C C

c

mol c r r 3

'1

t-1

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