Andriyevsky Bohdan, Tarrat Nathalie, Cortés Juan, Schön Johann Christian
Faculty of Electronics and Computer Science, Koszalin University of Technology, Śniadeckich Street 2, 74-453 Koszalin, Poland.
CEMES, Université de Toulouse, CNRS, 29 rue Jeanne Marvig, 31055 Toulouse, France.
R Soc Open Sci. 2022 Oct 12;9(10):220436. doi: 10.1098/rsos.220436. eCollection 2022 Oct.
Dehydrogenation and deprotonation of sucrose and trehalose molecules in vacuum is theoretically studied by using calculations in the framework of the density functional theory. The differences in the structural, electronic, energetic and vibrational properties of dehydrogenated and deprotonated molecules are discussed, depending on the site from which the hydrogen atom or the proton has been removed. The dehydrogenated molecules are found to be stable, regardless of which hydrogen atom is removed. This contrasts with the instability of the deprotonated molecules, where break-ups or structural reorganizations of the molecule are observed in 20-30% of the cases, but only when the hydrogen atom whose proton is removed was bonded to a carbon atom. Considering the stability and possible rearrangements of the hydrogen network of the deprotonated/dehydrogenated molecule, the formation of additional hydrogen-bridge bonds compared with the nominal molecule appears to be more pronounced for the deprotonated molecules than for the dehydrogenated ones. Moreover, our calculations show that the hydrogen-transfer energy barriers are usually larger for the deprotonated molecules than for the dehydrogenated ones. Finally, compared with the nominal molecule, the vibrational frequency spectrum is shifted to lower frequencies for both the dehydrogenated and the deprotonated molecules.
在密度泛函理论框架下，通过计算对真空中蔗糖和海藻糖分子的脱氢和去质子化进行了理论研究。根据氢原子或质子被移除的位置，讨论了脱氢和去质子化分子在结构、电子、能量和振动性质上的差异。发现无论移除哪个氢原子，脱氢分子都是稳定的。这与去质子化分子的不稳定性形成对比，在20% - 30%的情况下，会观察到分子的分解或结构重组，但只有当被移除质子的氢原子与碳原子相连时才会出现这种情况。考虑到去质子化/脱氢分子氢网络的稳定性和可能的重排，与标称分子相比，去质子化分子中额外氢键的形成似乎比脱氢分子更明显。此外，我们的计算表明，去质子化分子的氢转移能垒通常比脱氢分子的更大。最后，与标称分子相比，脱氢和去质子化分子的振动频率谱都向更低频率移动。
