Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, Université de Lille 1, F-59655 Villeneuve d'Ascq, France.
J Phys Chem A. 2010 Nov 25;114(46):12202-7. doi: 10.1021/jp108312w. Epub 2010 Oct 29.
The millimeter-wave rotational spectrum of vinyltellurol has been recorded and assigned for the first time. To support the spectrum assignment, high level ab initio calculations have been carried out. Geometries, total electronic energies, and harmonic vibrational frequencies have been determined at the MP2 level. A small-core relativistic pseudopotential basis set (cc-pVTZ-PP) was employed to describe the tellurium atom. Two stable conformers, synperiplanar (sp) and anticlinal (ac), have been identified. The sp conformer is planar with a small negative inertia defect of -0.025 u Å(2). The ac conformer was found to be nonplanar with a C-C-Te-H dihedral angle of about 140° from sp. This conformer exhibits a large amplitude motion associated with the torsion about the C-Te bond. The barrier to internal rotation is about 1 kJ/mol, according to the theoretical calculations. For the ac conformation, a torsional potential function consisting of quartic and quadratic terms of the torsional angle has been partially determined from the observed rotational constants.
首次记录并分配了乙烯碲醇的毫米波旋转光谱。为了支持光谱分配，进行了高水平的从头计算。在 MP2 水平上确定了几何形状、总电子能量和简谐振动频率。采用小核相对论赝势基组（cc-pVTZ-PP）来描述碲原子。已确定两种稳定构象，顺式（sp）和反式（ac）。sp 构象是平面的，惯性缺陷很小，为-0.025 u Å(2)。ac 构象是非平面的，与 sp 相比，C-C-Te-H 二面角约为 140°。该构象表现出与 C-Te 键扭转相关的大振幅运动。根据理论计算，内部旋转的势垒约为 1 kJ/mol。对于 ac 构象，从观察到的旋转常数中部分确定了由扭转角的四次项和二次项组成的扭转势能函数。
