The first automated 470.59 MHz 19F NMR-controlled titration:: dissociation constants and ion-specific chemical shifts of 2-amino-4-fluoro 2-methylpent-4-enoic acid

被引：1

作者：

Uhlemann, CE

Pfaff, CG

Hägele, G

Laue, KW

Lübke, M

Haufe, G

机构：

[1] Univ Dusseldorf, Inst Anorgan Chem & Strukturchem, D-40225 Dusseldorf, Germany

[2] Univ Munster, Inst Organ Chem, D-48149 Munster, Germany

来源：

MAGNETIC RESONANCE IN CHEMISTRY | 2002年 / 40卷 / 09期

关键词：

NMR; F-19; H-1; chemical shifts; F; H and H; H coupling constants; amino acid; dissociation constants; NMR titration; ion-specific NMR parameters;

D O I：

10.1002/mrc.1058

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

2-Amino-4-fluoro-2-methylpent-4-enoic acid, obtained as a 1:1 salt with trifluoro-acetic acid, was characterized by H-1 and F-19 high-resolution NMR spectroscopy. High-precision potentiometry led to the dissociation constants pK(a1) = 1.879 and pK(a2) = 9.054. The first automated 470.59MHz F-19 NMR-controlled titration yielded the dynamic chemical shift (delta(F)) as a function of pcH or tau and the ion-specific chemical shifts: delta(F)(H2L*) = -94.81 ppm, delta(F)(HL) = -94.21 ppm, delta(F)(L-) = -92.45 ppm. The deprotonation gradients were found to be Delta(1) = -0.60 ppm and Delta(2) = -1.76 ppm. Copyright (C) 2002 John Wiley Sons, Ltd.

引用

页码：573 / 580

页数：8