当前位置：
X-MOL 学术
›
J. Phys. Chem. A
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Rotational Spectrum, Tunneling Motions, and Intramolecular Potential Barriers in Benzyl Mercaptan
The Journal of Physical Chemistry A ( IF 2.7 ) Pub Date : 2019-09-18 , DOI: 10.1021/acs.jpca.9b06921 Rizalina Tama Saragi 1 , Marcos Juanes 1 , Walther Caminati 1 , Alberto Lesarri 1 , Lourdes Enríquez 2 , Martín Jaraíz 1, 2
The Journal of Physical Chemistry A ( IF 2.7 ) Pub Date : 2019-09-18 , DOI: 10.1021/acs.jpca.9b06921 Rizalina Tama Saragi 1 , Marcos Juanes 1 , Walther Caminati 1 , Alberto Lesarri 1 , Lourdes Enríquez 2 , Martín Jaraíz 1, 2
Affiliation
|
The rotational spectrum of benzyl mercaptan (parent and four isotopologues) has been assigned in a supersonic jet expansion using chirped-pulse Fourier transform microwave spectroscopy. The spectrum is characterized by torsional tunneling doublings, strongly perturbed by Coriolis interactions. The experimental rotational constants reveal that the sulfur atom is located above the ring plane in a gauche conformation. The torsion dihedral θ0 = φ (SCα–C1C2) is approximately 74°, according to a flexible molecular model calculation reproducing the energy separation (ΔE01 ∼ 2180.4 MHz) between the first two torsional substates. The global minimum configuration is 4-fold degenerate, corresponding to potential minima with θ0 ≈ ±74° and ±(180–74)°. The four equivalent minima are separated by potential barriers at θ = ±90°, 0°, or 180°. The tunneling splittings are caused by the potential barrier at θ = ± 90°, while the barriers at torsions of 0° or 180° are too large to generate detectable splittings. The tunnelling barrier has been determined as 248 cm–1, similar to the value obtained with high-level MP2 ab initio calculations (259 cm–1), but smaller than in benzyl alcohol (280 cm–1).
中文翻译：
苄硫醇中的旋转光谱，隧穿运动和分子内势垒
苄基硫醇（母体和四个同位素）的旋转光谱已通过chi脉冲傅里叶变换微波光谱法在超音速射流扩展中确定。该光谱的特征是扭转隧道效应加倍，受到科里奥利相互作用的强烈干扰。实验旋转常数表明，硫原子以薄纱构型位于环平面的上方。扭转二面角θ 0 =φ（SCα-C1C2）为大约74°，根据柔性分子模型计算再现的能量分离（Δ Ë 01的前两个扭转子状态之间〜2180.4兆赫）。全局最小配置为4倍简并，对应于θ0的潜在最小值≈±74°和±（180–74）°。四个等效极小值由θ=±90°，0°或180°的势垒分隔。隧穿裂缝是由θ=±90°的势垒引起的，而0°或180°扭转下的势垒太大而无法产生可检测的裂缝。隧穿势垒已确定为248 cm –1，与通过高级MP2从头计算得出的值（259 cm –1）相近，但小于苯甲醇（280 cm –1）。
更新日期：2019-09-18
中文翻译：
苄硫醇中的旋转光谱，隧穿运动和分子内势垒
苄基硫醇（母体和四个同位素）的旋转光谱已通过chi脉冲傅里叶变换微波光谱法在超音速射流扩展中确定。该光谱的特征是扭转隧道效应加倍，受到科里奥利相互作用的强烈干扰。实验旋转常数表明，硫原子以薄纱构型位于环平面的上方。扭转二面角θ 0 =φ（SCα-C1C2）为大约74°，根据柔性分子模型计算再现的能量分离（Δ Ë 01的前两个扭转子状态之间〜2180.4兆赫）。全局最小配置为4倍简并，对应于θ0的潜在最小值≈±74°和±（180–74）°。四个等效极小值由θ=±90°，0°或180°的势垒分隔。隧穿裂缝是由θ=±90°的势垒引起的，而0°或180°扭转下的势垒太大而无法产生可检测的裂缝。隧穿势垒已确定为248 cm –1，与通过高级MP2从头计算得出的值（259 cm –1）相近，但小于苯甲醇（280 cm –1）。
京公网安备 11010802027423号