Theoretical rovibrational characterization of the cis/trans-HCSH and H2SC isomers of the known interstellar molecule thioformaldehyde
Theoretical rovibrational characterization of the cis/trans-HCSH and H2SC isomers of the known interstellar molecule thioformaldehyde
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DOI：
10.1016/j.jms.2020.111273
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发表时间：
2020-03-01
影响因子：
1.4
通讯作者：
Fortenberry, Ryan C.
中科院分区：
文献类型：
--
作者：
Inostroza-Pino, Natalia;Palmer, C. Zachary;Fortenberry, Ryan C.
星际介质中丢失的硫可能隐藏在分子中，这些分子的光谱数据还没有用于任何天体物理观测，像H2 CS的异构体分子，一种已知的星际化合物。每个已知的星际分子都是ISM中相关分子存在和可检测性的指针。这项量子化学研究为观察顺式、反式和（3）A HSH以及（1）A（1）和（3）A“”H2SC提供了必要的光谱数据。已知硫代甲醛的CCSD（T）-F12/cc-pVTZ-F12四次力场的基准提供了平均为1.9 cm（-1）的气相实验的非谐振动频率，证明了计算的基频的可靠性。（1）A（1）H2SC形式在红外和毫米波区域具有明亮的光谱特征，但它是这组中能量最高的物质。反式六氯环己烷异构体是仅次于硫代甲醛的能量最低的异构体（43.69千卡/摩尔或1.90电子伏特），但顺式六氯环己烷异构体的能量稍高，其最亮的基频强度更高，偶极矩也更大，因此更有可能被观察到。这里确定的这些数据也可能有助于这些分子的实验室表征以及它们的化学可能如何进展。(C)2020爱思唯尔公司All rights reserved.
The missing sulfur of the interstellar medium may be hiding in molecules for which there are no spectral data yet available for any astrophysical observation, molecules like isomers of H2CS a known interstellar compound. Every known interstellar molecule is a pointer to the presence and detectability of related molecules in the ISM. This quantum chemical study provides the necessary spectral data for the observation of cis-, trans-, and (3)A HCSH as well as for (1)A(1) and (3)A '' H2SC. Benchmarks of the CCSD(T)-F12/cc-pVTZ-F12 quartic force field for the known thioformaldehyde provide anharmonic vibrational frequencies of with an average of 1.9 cm(-1) of gas-phase experiment demonstrating reliability for the computed fundamental frequencies. The (1)A(1) H2SC form has bright spectral features in the infrared and millimeter-wave regimes, but is the highest-energy species of this set. The trans-HCSH isomer is the lowest-energy (43.69 kcal/mol or 1.90 eV) isomer next to thioformaldehyde, but the slightly higher cis-HCSH isomer has greater intensities for its brightest fundamental frequencies and a larger dipole moment making it potentially more likely to be observed. These data determined here may also assist in laboratory characterization of these molecules and how their chemistry will likely progress. (C) 2020 Elsevier Inc. All rights reserved.