Spectral and calorimetric studies of hydrogen bonding with pyrrole
Spectral and calorimetric studies of hydrogen bonding with pyrrole
复制标题
吡咯氢键的光谱和量热研究
DOI：
10.1021/ja00727a012
复制
发表时间：
1970
影响因子：
15
通讯作者：
M. S. Nozari
中科院分区：
文献类型：
--
作者：
R. Drago;M. S. Nozari
实验测定了吡咯与部分Lewis碱之间氢键相互作用的NH频移和氢键作用的热焓。计算了吡咯的E值和C值，并用它们估算了吡咯与其他Lewis碱的加合物生成热，这些路易斯碱太弱，无法准确测量。将吡咯的数据与以前研究的氢键羟基酸的数据进行比较，结果表明，所有这些氢键体系的E和C参数的比值是相似的。吡咯是一种比酚类和1，1，1，3，3，3-六氟-2-丙醇弱的酸，但比零丁醇强。对于所研究的给体，-AH与Ayn_H(NH加合物形成时NH伸缩频率的变化)的关系图与羟基酸的情况一样是线性的，并服从定量关系：-AH=(0.0123±0.0006)·+1.8(±0.1)。根据本实验室和其他实验室有关醇氢键的其他报道关系，考虑了伴随加合物形成的热焓和光谱变化。
The NH frequency shiftsand the enthalpies of hydrogen-bonding interactions between pyrrole and selected Lewis bases were experimentally determined. E and C values for pyrrole were calculated and used to estimate the enthalpies of adduct formation for pyrrole with other Lewis bases which are too weak to measure accu-rately. Comparison of the data for pyrrole with previously studied hydrogen-bonding hydroxy acids indicates that the ratios of the E and C parameters for all these hydrogen-bonding systems are similar. Pyrrole is a weaker acid than the phenols and 1, 1, 1, 3, 3, 3-hexafluoro-2-propanol, but is stronger than Zert-butyl alcohol. For the donors studied, the plot of—AH vs. AyN_H (the change in NH stretching frequency upon adduct formation) is found to be linear, as in the case of the hydroxy acids, and obeys the quantitative relationship:—AH=(0.0123±0.0006)· _+ 1.8 (±0.1). The enthalpy and spectral changes accompanying adduct formation are considered in the light of other reported relationships from this and other laboratories pertaining to hydrogen bonding by alcohols.