First observation of different diffusion coefficients for two conformers in a neat liquid

被引：0

作者：

Liuping Chen

T. Gross

H.-D. Lüdemann

H. Krienke

R. Fischer

机构：

[1] Institut für Biophysik und Physikalische Biochemie,

[2] Universität Regensburg,undefined

[3] 93040 Regensburg,undefined

[4] Germany e-mail: Dietrich.Luedemann@biologie.uni.regensburg.de Tel.: +49-941-9432492 Fax: +49-941-9432479,undefined

[5] Institute of Physical Chemistry,undefined

[6] School of Chemistry and Chemical Engineering,undefined

[7] Zhongshan (Sun Yat-Sen) University,undefined

[8] Guangzhou 510275,undefined

[9] People's Republic of China,undefined

[10] Institut für Physikalische und Theoretische Chemie der Universität Regensburg,undefined

[11] 93040 Regensburg,undefined

[12] Germany,undefined

来源：

Naturwissenschaften | 2000年 / 87卷

关键词：

Experimental Study; Diffusion Coefficient; Dielectric Constant; Structural Property; Monte Carlo;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

Self-diffusion coefficients were studied for the highly polar liquid N-methylformamide at pressures up to 200 MPa between the melting pressure curves and 420 K by the spin-echo method. N-Methylformamide exists as a mixture of two conformers in the neat liquid. These conformers have large differences at lower temperatures in their dynamic and structural properties. The self-diffusion coefficient of the cis-conformer being 17% lower than that of the trans-conformer at the same T and p. This is the first observation of such an effect. The experimental study is supported by Monte Carlo (MC) calculations which show that the first neighbors around a cis conformer are arranged differently than in an all trans liquid. The difference leads in the simulations to a much lower dielectric constant for the trans-cis mixture and might also explain the retardation of diffusion for the cis conformer.

引用

页码：225 / 228

页数：3