Formation of carbamic acid in organic solvents and in supercritical carbon dioxide

被引：69

作者：

Dijkstra, Z. J.

Doornbos, A. R.

Weyten, H.

Ernsting, J. M.

Elsevier, C. J.

Keurentjes, J. T. F.

机构：

[1] Eindhoven Univ Technol, Dept Chem Engn & Chem, Proc Dev Grp, SPD, NL-5600 MB Eindhoven, Netherlands

[2] Vito, Flemish Inst Technol Res, B-2400 Mol, Belgium

[3] Univ Amsterdam, Fac Sci, Vant Hoff Inst Mol Sci, NL-1018 WV Amsterdam, Netherlands

来源：

JOURNAL OF SUPERCRITICAL FLUIDS | 2007年 / 41卷 / 01期

关键词：

NMR; supercritical CO(2); amine; carbamic acid;

D O I：

10.1016/j.supflu.2006.08.012

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The behavior of amines in various CO(2)-rich solvents is described. (1)H and (13)C NMR spectra in DMSO, chloroform, and benzene show that the amines are completely converted into carbamic acid by just bubbling atmospheric CO(2) through the solution. However, the chemical shifts of several protons and the carbonyl (13)C in the newly formed compounds strongly depend on the organic solvent used. FT-IR measurements confirm the observation that carbamic acid formation occurs. Changing the solvent to supercritical CO(2) shows a temperature- and pressure-dependent equilibrium between the amine and the carbamic acid; higher pressures shift the equilibrium towards the carbamic acid, whereas higher temperatures favor the free amine. (c) 2006 Elsevier B.V. All rights reserved.

引用

页码：109 / 114

页数：6

共 34 条

[1] Halogen-free process for the conversion of carbon dioxide to urethanes by homogeneous catalysis [J].