Istituto per lo Studio dei Materiali Nanostrutturati (ISMN, Sezione di Bologna), CNR, Via Gobetti 101, I-40129 Bologna, Italy.
J Phys Chem A. 2011 Sep 1;115(34):9493-7. doi: 10.1021/jp112015r. Epub 2011 Mar 15.
The rotational spectra of five isotopologues of the molecular adduct 1,1,1-trifluoroacetone-water have been assigned using pulsed-jet Fourier-transform microwave spectroscopy. All rotational transitions appear as doublets, due to the internal rotation of the methyl group. Analysis of the tunneling splittings allows one to determine accurately the height of the 3-fold barrier to internal rotation of the methyl group and its orientation, leading to V(3) = 3.29 kJ·mol(-1) and ∠(a,i) = 67.5°, respectively. The water molecule is linked to the keton molecule on the side of the methyl group through a O-H···O hydrogen bond and a C-H···O intermolecular contact, lying in the effective plane of symmetry of the complex.
采用脉冲喷射傅里叶变换微波光谱法对 1,1,1-三氟丙酮-水的 5 种同位素加合物的转动光谱进行了分配。由于甲基的内旋转，所有的转动跃迁都表现为双峰。对内旋转的 tunneling 分裂的分析可以准确地确定甲基内旋转的 3 重势垒的高度及其取向，分别导致 V(3) = 3.29 kJ·mol(-1)和 ∠(a,i) = 67.5°。水分子通过 O-H···O 氢键和 C-H···O 分子间接触与酮分子连接在甲基的一侧，位于复合物的有效对称面上。
