Studies of linear correlation factor of dielectric polarization and excess dipolar free energies of amides in apolar solvents

Pramana

R Sabesan¹  M Malathi1²  S Krishnan¹ 

[1] Department of Physics, Annamalai University, Annamalai Nagar 608 002, India$$;Department of Physics, Vellore Institute of Technology, Vellore 632 014, India$$

关键词: Dielectric constants;    amides;    Kirkwood–Frohlich correlation factor;    Eyring’s significant structure theory;    dipolar excess free energies.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

The Kirkwood–Frohlich correlation factor (𝑔), Eyring's parameters 𝐺 and 𝐺* and the dipolar excess free energies of dilute solutions of formamide, acetamide, 𝑁-methyl acetamide, 𝑁, 𝑁-dimethyl formamide and 𝑁, 𝑁 -dimethyl acetamide in 1,4-dioxan/benzene were obtained from a measurement of their static dielectric permittivities at 308 K. The fluid structure of these amides is discussed. Both in formamide and acetamide a dimeric linear chain with the individual dipoles more or less parallely oriented is preferred. In 𝑁-methyl acetamide, the antiparallel orientation of dipoles at lower concentrations turns into a parallel orientation with increase of concentration. In tertiary amides, with increase of concentration, parallel orientation of dipoles with global value of 𝑔 tending to unity is observed. The dipolar excess free energy of mixing in a given solvent is of the order primary amide > secondary amide > tertiary amide.

【 授权许可】

Unknown