FC(O)SNCO的电子结构和光电离解离过程

由于拥有―C(O)S―和―NCO基团, FC(O)SNCO的分子和电子结构是非常有趣的. 利用FC(O)SCl和AgNCO制备了FC(O)SNCO,并利用HeI光电子能谱(PES)、光电离质谱(PIMS)以及理论计算研究了其分子和电子结构. 通过将实验、理论计算以及自然键轨道(NBO)分析结合起来, 获得了FC(O)SNCO的最稳定分子构型. 利用外壳层格林函数(OVGF)方法以及与相似化合物的比较, 对其光电子能谱进行了指认. 理论计算表明,对于中性分子最稳定的构型为syn-syn非平面构型, 而电离后的离子最稳定构型为syn-syn平面构型. 实验结果表明, 第一电离能来自于S的孤对电子轨道, 为10.33 eV. 第二至第六电离能分别为12.03、13.23、13.77、14.78、15.99 eV, 并对这些电离能进行了指认. 在光电离质谱中产生了六个质谱峰, 分别为SN⁺、FC(O)⁺、SNCO⁺、FC(O)SN⁺、C(O)SNCO⁺、FC(O)SNCO^+·, 其中FC(O)SNCO^+·的峰是最强峰. 结合HeI光电子能谱和理论计算, 对PIMS进行了分析,并研究了可能的电离和解离过程并对其进行了讨论.

Electronic Structure and Photoionization Dissociation Process of FC(O)SNCO

(Fluorocarbonyl) sulfenyl isocyanate (FC(O)SNCO) contains ―C(O)S― and ―NCO groups, so has an interesting electronic and molecular structure. FC(O)SNCO was prepared by the metathesis of FC(O)SCl and AgNCO. HeI photoelectron spectroscopy (PES), photoionization mass spectrometry (PIMS), and theoretical calculations were used to study the molecular and electronic structure of FC(O)SNCO. The experimental, theoretical calculations, and NBO results indicated the most stable conformer of FC(O)SNCO. In addition to the outer-valence Green''s function calculation, the PES spectrumwas assigned fromanalogous studies of similar molecules. The syn-syn non-planar conformer (δ_FCSN=180°) with C₁ symmetry was favored by the neutral molecule, and changed to the syn-syn planar structure with C_s symmetry after ionization. The experimental first vertical ionization potential mainly fromthe S lone pair orbital was 10.33 eV. The second to sixth ionization potentials of FC(O)SNCO were 12.44, 13.23, 13.77, 14.78, and 15.99 eV, respectively, and were also assigned. The FC(O)⁺, SN⁺, FC(O)SN⁺, SNCO⁺, C(O)SNCO⁺, and FC(O)SNCO^+· peaks were observed in the PIMS spectrum, the highest intensity of which was FC(O)SNCO^+·. The PIMS data were analyzed based on the PES and theoretical results. Possible ionization and dissociation processes are discussed.