Department of Chemistry, University of Copenhagen , Universitetsparken 5, DK-2100 Copenhagen, Denmark.
J Phys Chem A. 2013 Oct 10;117(40):10260-73. doi: 10.1021/jp405512y. Epub 2013 Sep 25.
Gas-phase vibrational spectra of 2-aminoethanol and 3-aminopropanol were recorded up to the third OH-stretching overtone using Fourier transform infrared spectroscopy, cavity ringdown spectroscopy, and intracavity laser photoacoustic spectroscopy. The experimental investigation was supplemented by local mode calculations, and the intramolecular interactions were investigated using atoms in molecules (AIM) and noncovalent interactions (NCI) theories. All calculations were performed at the CCSD(T)-F12a/VDZ-F12 level of theory. For both compounds the most abundant conformer has a structure that allows for hydrogen bond interaction from the OH group to the N atom of the amino group (OH-N). The spectra show signals from both hydrogen bonded and free OH stretches, implying the presence of several conformers. We observe hydrogen-bond-like interactions in both compounds. The red shift of the bonded OH-stretching frequency and intensity enhancement of the fundamental transition suggest that the hydrogen bond interaction is more pronounced in 3-aminopropanol. AIM analysis supports the presence of a hydrogen bond in 3-aminopropanol but not in 2-aminoethanol, whereas NCI analysis shows hydrogen bonding in both compounds with the stronger interaction found in 3-aminopropanol.
采用傅里叶变换红外光谱、腔衰荡光谱和腔内激光光声光谱技术，记录了 2-氨基乙醇和 3-氨基-1-丙醇的气相振动光谱，直至第三 OH 伸缩泛频。实验研究得到了局部模式计算的补充，并使用分子中的原子（AIM）和非共价相互作用（NCI）理论研究了分子内相互作用。所有计算均在 CCSD(T)-F12a/VDZ-F12 理论水平上进行。对于这两种化合物，最丰富的构象允许 OH 基团与氨基的 N 原子之间发生氢键相互作用（OH-N）。光谱显示了氢键和游离 OH 伸缩的信号，表明存在几种构象。我们观察到这两种化合物中都存在氢键样相互作用。结合 OH 伸缩频率的红移和基频跃迁的强度增强表明，3-氨基-1-丙醇中的氢键相互作用更为明显。AIM 分析支持 3-氨基-1-丙醇中存在氢键，但 2-氨基乙醇中不存在氢键，而 NCI 分析表明两种化合物中均存在氢键，在 3-氨基-1-丙醇中氢键相互作用更强。
