STATISTICAL INTERPRETATION OF ENTHALPY-ENTROPY COMPENSATION
STATISTICAL INTERPRETATION OF ENTHALPY-ENTROPY COMPENSATION
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DOI：
10.1038/261566a0
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发表时间：
1976-01-01
期刊：
影响因子：
64.8
通讯作者：
GRIEGER, RA
中科院分区：
文献类型：
--
作者：
KRUG, RR;HUNTER, WG;GRIEGER, RA
典型地，从动力学和平衡数据估计的焓和熵是高度相关的，以线性方式彼此变化（焓-熵补偿效应）。在大多数情况下，这种效应可以简单地解释为统计或数据处理的假象。这里提出的统计分析揭示了三个新的见解。首先，焓和熵参数估计是高度相关的，使得估计的相关系数> 0.95，比如说，并不意味着化学因果关系。第二，焓和熵的估计分布在椭圆概率区域的实验和测量误差是非常细长的，并出现作为线。这些线的斜率是实验温度的调和平均值。第三，在实验温度的调和平均值下的焓和自由能的估计值在统计上是不相关的，因此这些参数估计值之间的任何观察到的结构性变化仅来自化学效应。注意，由于热力学势通过麦克斯韦关系式相互关联，因此可以将任意两个势之间的相关性变换为任意其他两个势之间的对应相关性。我们现在讨论这些结果，以解决有关一个有争议的数据集的一些问题。
TYPICALLY, enthalpy and entropy estimates from kinetic and equilibrium data are highly correlated, varying in a linear fashion with one another (enthalpy–entropy compensation effect). This effect can be readily explained in most cases simply as a statistical or data handling artefact. The statistical analysis presented here reveals three novel insights. First, the enthalpy and entropy parameter estimates are highly correlated, such that estimated correlation coefficients > 0.95, say, do not imply chemical causation. Second, enthalpy and entropy estimates are distributed by experimental and measurement errors in elliptical probability regions that are very elongated and appear as lines. The slope of such lines is the harmonic mean of the experimental temperatures. Third, estimates of enthalpy and free energy at the harmonic mean of the experimental temperatures are not statistically correlated, so any observed structured variation between these parameter estimates arises from the chemical effect alone. Note that, since the thermodynamic potentials are interrelated by the Maxwell relationships, a correlation between any two potentials can be transformed to give the corresponding correlation between any other two. We now discuss these results to resolve a number of issues concerning a much disputed data set.