NUCLEAR MAGNETIC RESONANCE MEASUREMENTS IN SOLUTIONS OF ACETYLACETONE: THE EFFECT OF SOLVENT INTERACTIONS ON THE TAUTOMERIC EQUILIBRIUM
NUCLEAR MAGNETIC RESONANCE MEASUREMENTS IN SOLUTIONS OF ACETYLACETONE: THE EFFECT OF SOLVENT INTERACTIONS ON THE TAUTOMERIC EQUILIBRIUM
复制标题
乙酰丙酮溶液中的核磁共振测量：溶剂相互作用对互变平衡的影响
DOI：
10.1139/v57-179
复制
发表时间：
1957
影响因子：
1.1
通讯作者：
L. W. Reeves
中科院分区：
文献类型：
--
作者：
L. W. Reeves
一个修改后的分配的PMR信号在乙酰丙酮被确认。所选信号的强度随温度的变化用于计算2700 ± 100 cal的转化焓。 之间的酮和烯醇形式在纯乙酰丙酮。相互作用，扰乱之间的互变异构形式在稀溶液中形成的溶液络合物的平衡，通过观察在各种溶剂中的稀释化学位移进行了研究。酮与烯醇形式的比率通过测量每种溶剂中几种稀释度下的信号强度来估计。与伯恩斯坦和Powling（5）的关联式的偏差，即溶剂介电常数与摩尔体积之间的偏差，以及稀溶液中互变异构平衡的位置，被用作溶剂相互作用的判据。它们与目前的测量结果是一致的。典型的碱性，酸性，两性和中性溶剂已被选择来调查可能的相互作用类型。环己烷和乙酸不对...
A modified assignment of the PMR signals in acetylacetone is confirmed. The changes in intensity of selected signals with temperature are used to calculate an enthalpy of conversion of 2700 ± 100 cal. between keto and enol forms in pure acetylacetone.Interactions, which perturb the equilibrium between the tautomeric forms in dilute solution by formation of solution complexes, are studied by observing dilution chemical shifts in various solvents. The ratio of keto to enol forms is estimated from measurements of signal intensities at several dilutions in each solvent. The deviations from the correlations of Bernstein and Powling (5) between solvent dielectric constant and molar volume, and the position of the tautomeric equilibrium in dilute solutions, have been used as a criterion of solvent interaction. They are consistent with the present measurements.Typical basic, acidic, amphoteric, and neutral solvents have been chosen to investigate possible types of interaction. Cyclohexane and acetic acid do not p...