<span style="font-size:22.5pt;mso-bidi-font-size:15.5pt; line-height:115%;font-family:"Times New Roman","serif";mso-fareast-font-family: "Times New Roman";mso-fareast-theme-font:minor-fareast;mso-ansi-language:EN-US; mso-fareast-language:EN-US;mso-bidi-language:AR-SA;mso-bidi-font-weight:bold">Study of dipole moment of 18-crown-6 in CCI₄<span style="font-size: 17.5pt;mso-bidi-font-size:10.5pt;line-height:115%;font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman";mso-fareast-theme-font:minor-fareast; mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA; mso-bidi-font-weight:bold"> <span style="font-size:22.5pt;mso-bidi-font-size: 15.5pt;line-height:115%;font-family:"Times New Roman","serif";mso-fareast-font-family: "Times New Roman";mso-fareast-theme-font:minor-fareast;mso-ansi-language:EN-US; mso-fareast-language:EN-US;mso-bidi-language:AR-SA;mso-bidi-font-weight:bold">solutions at 298.15 K</span></span></span>

Abstract

46-51<span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">Dielectric constant <span style="font-size:14.0pt;mso-bidi-font-size:7.0pt; font-family:" times="" new="" roman","serif""="">(Ɛ), <span style="font-size:15.0pt; mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">density (d) <span style="font-size:15.0pt;mso-bidi-font-size:8.0pt;font-family: " times="" new="" roman","serif""="">and refractive index (<i style="mso-bidi-font-style: normal">n) measurements at 298.15 K for solutions or 18-crown-6 in CCI4(0.5 to 25 ×10-3 weight fraction of solute) have been reported. The data, along with partial molar volume data for solute are subjected to analysis using various equations to obtain solute polarization and dipole moment values at finite and infinitely dilute concentrations. The dipole moment value of 3.5 D has been compared with gas-phase value and the values in solutions of benzene and cyclohexane, reported earlier. The unexpected large value of dipole moment obtained has been discussed in terms or conformation adopted by the cyclic polyether in a solvent environment. <span style="font-size:15.5pt;mso-bidi-font-size:8.5pt; font-family:" arial","sans-serif""="">It <span style="font-size:15.0pt; mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">is further explained that, in solution phase if 18C6 molecules exist in Ci symmetry conformation (this cannot have dipole moment), the atomic polarization via -CH2- chains must be making large contribution to account for the observed solute polarization. </span