Department of Chemistry, Kent State University, Kent, Ohio 44242, USA.
J Phys Chem A. 2010 Jan 14;114(1):336-42. doi: 10.1021/jp908351u.
Rotational spectra were recorded in natural abundance for the (13)C isotopomers of two conformers of glycidol. Moments of inertia from the (13)C isotopomers were used to calculate the substitution coordinates and C-C bond lengths of two glycidol monomer conformations. The structures of seven different conformational minima were found from ab initio (MP2/6-311++G(d,p)) optimizations of glycidol-water. The rotational spectrum of glycidol-water was recorded using microwave spectroscopy, and the rotational constants were determined to be A = 3902.331 (11) MHz, B = 2763.176 (3) MHz, and C = 1966.863 (3) MHz. Rotational spectra were also recorded for glycidol-H(2)(18)O, glycidol-D(b)OH, and glycidol-d(O)-D(2)O. The rotational spectra were assigned to the lowest-energy ab initio structure, and the structure was improved by fitting to the experimental moments of inertia. The best-fit structure shows evidence for structural changes in glycidol to accommodate formation of the intermolecular hydrogen bonding network: the O-C-C-O torsional angle in glycidol was found to increase from 40.8 degrees for the monomer to 49.9 degrees in the water complex.
旋转光谱以天然丰度记录了缩水甘油的两种构象的 (13)C 同位素。从 (13)C 同位素的转动惯量计算了两种缩水甘油单体构象的取代坐标和 C-C 键长。通过对缩水甘油-水的从头算（MP2/6-311++G(d,p)）优化，发现了七种不同的构象最低能。使用微波光谱法记录了缩水甘油-水的旋转光谱，并确定了旋转常数为 A = 3902.331 (11) MHz、B = 2763.176 (3) MHz 和 C = 1966.863 (3) MHz。还记录了缩水甘油-H(2)(18)O、缩水甘油-D(b)OH 和缩水甘油-d(O)-D(2)O 的旋转光谱。旋转光谱被分配给最低能量的从头算结构，并通过拟合实验转动惯量来改进结构。最佳拟合结构表明，为了适应形成分子间氢键网络，缩水甘油的结构发生了变化：在单体中，O-C-C-O 扭转角从 40.8 度增加到水复合物中的 49.9 度。
