Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA.
J Chem Phys. 2009 Nov 28;131(20):204307. doi: 10.1063/1.3266944.
The dichlorothiophosphoryl (Cl(2)PS) free radical has been identified in the gas phase for the first time by a combination of laser-induced fluorescence and single vibronic level emission spectroscopy. High level ab initio calculations of the properties of the ground and first two excited states have been undertaken to aid in the interpretation of the data. The radicals were produced by an electric discharge through a dilute mixture of Cl(3)PS in high pressure argon at the exit of a pulsed supersonic expansion. An extensive band system was observed in the 760-560 nm region and has been assigned as the B (2)A(')-X (2)A(') electronic transition in which an electron in the ground state pi orbital is promoted to the pi( *) orbital. Three excited state and four ground state vibrational frequencies and their chlorine isotope effects have been measured and found to be in good accord with the theoretical predictions. Theory indicates that the radical is nonplanar in the ground state with increased pyramidalization and a longer PS bond in the first (A (2)A(") n-pi( *)) and second excited electronic states.
二氯硫膦（Cl(2)PS）自由基首次通过激光诱导荧光和单振子能级发射光谱的组合在气相中被识别。进行了高精度从头算计算，以研究基态和前两个激发态的性质，以帮助解释数据。自由基是通过在高压氩气中的 Cl(3)PS 稀混合物中进行放电，在脉冲超音速膨胀的出口处产生的。在 760-560nm 区域观察到广泛的带系，并将其分配为 B（2）A('）-X（2）A('）电子跃迁，其中基态 pi 轨道中的电子被提升到 pi()轨道。已经测量了三个激发态和四个基态振动频率及其氯同位素效应，并发现它们与理论预测非常吻合。理论表明，该自由基在基态时是非平面的，在第一（A（2）A(") n-pi()）和第二激发电子态中，三角锥形结构增加，PS 键变长。
