Ultrasonic Speed and Related Acoustical Parameters of 1,1ʼ-Binaphthalene-2,2ʼ-diyl Diacetate Solutions at 308.15 K

Pooja P Adroja,P H Parsania,J P Patel,S P Gami

doi:10.1155/2011/869594

Abstract

The density (ρ), viscosity (η) and ultrasonic speed (U) (2 MHz) of chloroform, THF, ethyl alcohol, ethyl acetate, 1,4-dioxane and 1,1ʼ-binaphthalene-2,2ʼ-diyl diacetate (DBNA) solutions have been determined at 308.15 K. Various acoustical parameters namely specific acoustical impedance (Z), adiabatic compressibility (κa), Van der Waals constant (b), intermolecular path length (Lf), internal pressure (π), Raoʼs molar sound function (R), relaxation time (τ), classical absorption coefficient (α/f2)cland solvation number (Sn) have been derived from ρ, η and U data and correlated with concentration (C). A fairly good to excellent correlation has been observed between a particular parameter and C. Linear increase of Z, R, b, (α/f2)cland τ (except EA) (R2= 0.90 – 0.999) and linear decrease of κs, π and Lf(R2= 0.947 – 0.995) with C supported existence of powerful molecular interactions in the solutions and further supported by nonlinear increase of Snwith C. A fairly constant Gibbs free energy of activation has been observed in all the solvent systems studied.

Highlights

Novel materials with controlled stereochemistry have found numerous applications. 2,2’-Substituted 1,1’-binaphthyl systems have been found extensively useful because of their stable conformation1. (R) or (S) - BINOLS have often been used as the starting materials for obtaining chiral binaphthyl compounds, leading to a variety of binaphthyl derivatives, which can exhibit remarkably stable chiral configuration as well as high chiral induction in many asymmetric processes[2]
The least squares equations along with regression coefficients (R2) are summarized in Table 2 from which it is observed that a fairly good to excellent correlation is found between said parameters and C (0.904 - 0.999)
Various acoustical parameters namely specific acoustical impendence (Z), adiabatic compressibility, Rao’s molar sound function (R), Van der Waals constant (b), intermolecular free path length (Lf), internal pressure (π), relaxation time (τ), classical absorption coefficient (α/f2)cl and solvation number (Sn) were derived using ρ, η and U data according to our recent publications[7,11,12] and correlated with C

Summary

Introduction

Novel materials with controlled stereochemistry have found numerous applications. 2,2’-Substituted 1,1’-binaphthyl systems have been found extensively useful because of their stable conformation1. (R) or (S) - BINOLS have often been used as the starting materials for obtaining chiral binaphthyl compounds, leading to a variety of binaphthyl derivatives, which can exhibit remarkably stable chiral configuration as well as high chiral induction in many asymmetric processes[2].The measurement of speed of sound in liquid mixtures and solutions has been found to be important tool to study the physicochemical properties of the mixtures and solutions[3]. Lf (R2 = 0.947 – 0.995) with C supported existence of powerful molecular interactions in the solutions and further supported by nonlinear increase of Sn with C. The measurements of physical properties such as density(ρ), refractive index (n), coefficient of viscosity(η), ultrasonic velocity (U), molar sound velocity or Rao’s number(R), molar volume (υf), adiabatic compressibility (β), characteristic acoustic impedance(Z), inter molecular or free length(Lf), free volume (Vf), available volume(Va) play an important role in sound transmission in different organic solvents and solutions.

Results

Conclusion