The photolysis of thionyl chloride (Cl₂SO) in pure cyclohexane (cHex) and in cHex with a small amount of tetrahydrofuran (THF) irradiated with 266 nm pulsed laser was investigated using time-resolved step-scan Fourier-transform spectroscopy. The density functional theory B3LYP, with the conductor-like polarizable continuum model to account for the effects of solvents, was employed to predict the molecular parameters of the relevant species. Monitoring the wavenumbers and infrared absorbances attributed to the [S,O] species and accounting for the stoichiometry revealed SO₂ to be the major oxygen-containing end product for the thermal decomposition of Cl₂SO. Upon successive irradiation with 266 nm pulsed laser, the major product, as detected by IR absorption, was S₂O with minor SO₃, which could be generated from the secondary reactions of the photolytic intermediate ClSO. The majority of the transient vibrational features upon 266 nm irradiation of the mixture of Cl₂SO/cHex was attributed to ClSO, characterized at 1155 cm^–1, coupled with a minor contribution of (ClSO)₂ at 1212 and 1173 cm^–1. For the mixture of Cl₂SO/THF/cHex, the transient population of ClSO was retained, but the amount of (ClSO)₂ was slightly reduced, coupled with a new upward feature at 1054 cm^–1 that was plausibly attributed to the C–O–C asymmetric stretching mode of ClSO–THF complex. Upon the successive irradiation of the Cl₂SO/THF/cHex mixture, the amount of S₂O was also decreased. The observed complexes of THF with solutes suggested that THF should not be merely treated as a solvent but regarded as a coordination molecule in organic synthesis. The formation of the intermediate–THF complexes altered the reaction pathways, as well as the types and populations of the end products.

中文翻译：

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在环己烷中亚硫酰氯（Cl ₂ SO）的光解中，四氢呋喃（THF）表现得像溶剂或反应物吗？瞬态红外差异研究

使用时间分辨步进扫描傅里叶变换光谱法研究了亚硫酰氯（Cl ₂ SO）在纯环己烷（cHex）和cHex中与少量266 nm脉冲激光照射的四氢呋喃（THF）的光解。密度泛函理论B3LYP结合了类似导体的可极化连续体模型来考虑溶剂的影响，被用来预测相关物种的分子参数。监测归因于[S，O]物种的波数和红外吸收率并解释化学计量表明，SO ₂是Cl ₂热分解的主要含氧终产物。所以。在用266 nm脉冲激光连续照射后，通过红外吸收检测，主要产物为S ₂ O和少量SO ₃，这可能是由光解中间体ClSO的二次反应产生的。Cl ₂ SO / cHex混合物在266 nm辐照下的大部分瞬态振动特征归因于ClSO，特征在于1155 cm ^-1，而在1212和1173 cm ^-1处的（ClSO）₂贡献较小。对于Cl ₂ SO / THF / cHex的混合物，ClSO的瞬态种群得以保留，但（ClSO）_2的量略有减少，并在1054 cm ^–1处具有新的向上特征。这可能归因于ClSO-THF配合物的C–O–C不对称拉伸模式。在连续辐照Cl ₂ SO / THF / cHex混合物后，S ₂ O的量也减少了。观察到的THF与溶质的络合物表明THF不应仅被视为溶剂，而应被视为有机合成中的配位分子。中间体-THF配合物的形成改变了反应途径，以及最终产物的类型和种群。