Study On Transient Molecules Containing Phosphorus And/or Chlorine By Velocity/Concentration Modulation Spectroscopy

The study of transients in chemical reactions has been of the great interests of physical scientists for a few decades. Comprehensive studies of transient molecules improve our understanding of the structure of matter and the essence of chemical reactions, which will help us to realize the control of the generation of species and the reactions of interests.Transient molecules containing phosphorus and/or chlorine play important roles in astrophysics, dynamics of chemical reaction, plasma, atmospheric chemistry and many other relevant fields. Their rotation-resolved electronic transition absorption spectrum contains abundant information on structure and dynamics of molecule, which can serve as the basic evidences for fundamental science in these fields. In this dissertation the high resolution electronic transition absorption spectra of several transient species containing P and/or Cl have been observed using optical heterodyne magnetic rotation enhanced velocity/concentration modulation spectroscopy (OH-MR-VMS/CMS) and the analysis of the observed spectra has been performed. Moreover, the experimental technology and the method of molecular structure theoretical analysis have been constructed for the selective detection of ions or neutrals, the paramagnetic or the diamagnetic, the highly efficient and accurate assignment of the spectra and the acquisition of the information about the precise molecular structure and the detail of the involved chemical reactions.The parent molecule PCl₃ buffering by vast helium was used to generate the P and/or Cl containing transient species in an ac glow discharge. Its absorption spectrum was obtained using highly-sensitive spectroscopy, OH-MR-VMS/CMS. Meanwhile, the parent gases Cl₂ and P4 were, respectively, used for each spectrum obtaining in order to experimentally discriminate the complex products of PCl₃ and to clarify detail of reaction processes.The A²Î _u-X²Î _g absorption spectrum of Cl₂⁺ has been recorded in the ac discharge of Cl₂/He using OH-MR-VMS. The little magnetic enhancement of the spectrum confirms the identity of the bands due to theΩ=1/2 component of the electronic transition in spite of the paramagnetic feature of Cl₂⁺. The assigned bands are (3, 7) band of theΩ= 1/2 component of ³⁵Cl₂⁺ and ³⁵Cl³⁷Cl+ and (2, 7) band of theΩ= 1/2 component of ³⁵Cl₂⁺. It extends the range of vibrational assignments...