Department of Physical Chemistry, Kazan Federal University, Kremlevskaya 18, Kazan 420008, Russia.
Molecules. 2021 Mar 5;26(5):1411. doi: 10.3390/molecules26051411.
In the present work, the thermochemistry of solution, solvation, and hydrogen bonding of cyclic amides in proton acceptor (B) and proton donor (RXH) solvents were studied. The infinite dilution solution enthalpies of δ-valerolactam, -methylvalerolactam, ε-caprolactam, and -methylcaprolactam were measured at 298.15 K. The solvation enthalpies of cyclic amides were calculated based on the measured solution enthalpies and sublimation/vaporization enthalpies from literature. The enthalpies of hydrogen bonding between cyclic amides and proton acceptor and donor solvents were then calculated as a difference between the total solvation enthalpy and the non-specific contribution. The latter was estimated via two different approaches in proton donor and proton accepting solvents. The effect of the cycle size on the strength of hydrogen bonding of the cyclic amides in solution is discussed.
在本工作中，研究了环状酰胺在质子受体（B）和质子给体（RXH）溶剂中的溶液热化学、溶剂化和氢键作用。在 298.15 K 下测量了 δ-戊内酰胺、-甲基戊内酰胺、ε-己内酰胺和 -甲基己内酰胺的无限稀释溶液焓。基于测量的溶液焓和文献中的升华/蒸发焓，计算了环状酰胺的溶剂化焓。然后，通过两种不同的方法在质子给体和质子受体溶剂中计算环状酰胺与质子受体和给体溶剂之间氢键的焓。后者通过两种不同的方法在质子给体和质子受体溶剂中进行了估计。讨论了环大小对环状酰胺在溶液中氢键强度的影响。
