Aviles-Moreno Juan-Ramon, Demaison Jean, Huet Thérèse R
Contribution from the Laboratoire de Physique des Lasers, Atomes et Molécules, Bâtiment P5, UMR 8523 CNRS, Université Lille 1, F-59655 Villeneuve d'Ascq Cedex, France.
J Am Chem Soc. 2006 Aug 16;128(32):10467-73. doi: 10.1021/ja062312t.
Conformational flexibility in the smallest hydrated sugar, the glycolaldehyde-water complex, has been investigated in the gas phase by means of a combination of a microwave Fourier transform spectroscopy experiment in a supersonic molecular beam and ab initio quantum chemistry calculations. The water molecule inserts into glycolaldehyde using H-bonding selectivity: the two lowest energy conformations are stabilized by two intermolecular hydrogen bonds, and the next two by one intra- plus one intermolecular hydrogen bond. A dynamical flexibility associated with the two lowest energy conformations has been experimentally observed and accurately modeled with a two-dimensional potential energy surface involving the hydroxyl group and the free OH water group coordinates. The conclusions drawn from the role played in the conformational flexibility by the hydroxyl and carbonyl groups are extended to other carbohydrates and biomolecules.
最小的水合糖——乙醇醛 - 水络合物的构象灵活性，已在气相中通过将超声分子束中的微波傅里叶变换光谱实验与从头算量子化学计算相结合的方法进行了研究。水分子利用氢键选择性插入乙醇醛中：两个能量最低的构象由两个分子间氢键稳定，接下来的两个构象由一个分子内氢键加一个分子间氢键稳定。与两个能量最低的构象相关的动态灵活性已通过实验观察到，并使用涉及羟基和游离OH水基团坐标的二维势能面进行了精确建模。从羟基和羰基在构象灵活性中所起的作用得出的结论扩展到了其他碳水化合物和生物分子。
