The Microwave Spectra of Isotopic Thiophosphoryl Chlorides in the Ground andv6= 1 Vibrational States

✍ Scribed by Steven Firth; R.Wellington Davis

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 258 KB
• Volume: 179
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1996.0181

✦ Synopsis

The pure rotational spectra of five isotopic species of thiophosphoryl chloride, SPCl 3 , have been examined in detail in the frequency range 26 -110 GHz. This study has shown that the frequencies previously reported for the rotational transitions of three symmetric-top species of SPCl 3 in the ground state are, in fact, due to molecules in the vibrationally excited state £ 6 Å 1. In this work we have measured for the first time rotational transitions for the 32 SP 35 Cl 3 , 34 SP 35 Cl 3 , and 32 SP 37 Cl 3 symmetric-top species in their ground vibrational states. In order to determine an accurate molecular geometry, the spectra of the asymmetric-top species 32 SP 35 Cl 2 37 Cl and 32 SP 35 Cl 37 Cl 2 were also recorded. The data obtained have been analyzed to yield values for rotational constants and quartic centrifugal distortion constants. Our results have been used, together with literature vibrational data, to refine an accurate harmonic force field for SPCl 3 . We have also evaluated effective, substitution, average, and approximate equilibrium values for internuclear parameters. The ground state average structural parameters of SPCl 3 are r z ( PS ) Å 1.8835 ( 7 ) A ˚, r z ( PCl ) Å 2.0093 ( 3 ) A ˚, and Є( SPCl ) Å 116.35 ( 2 ) Њ.