High-Resolution FTIR and Millimeter-Wave Study of D3SiF: The Ground, v3 = 1, and v6 = 1 and 2 States

✍ Scribed by N.Ben Sari-Zizi; H Najib; H Bürger; E.B Mkadmi; Z Kisiel; M.Yu Tretyakov; J Demaison; L Margulès; P Pracna

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 313 KB
• Volume: 197
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1999.7896

✦ Synopsis

The 6 (555.453 cm Ϫ1 ), the 3 (888.899 cm Ϫ1 ), and the very weak 2 6 infrared bands (2 6 ϯ2 1101.734 cm Ϫ1 , 2 6 0 1100.102 cm Ϫ1 ) for the 28 Si species of D 3 SiF have been recorded with a resolution of 3.3, 2.4, and 5.0 ϫ 10 Ϫ3 cm Ϫ1 , respectively. Millimeter-wave spectra up to 640 GHz of D 3 SiF in the ground, v 3 ϭ 1, and v 6 ϭ 1 and 2 states were measured. Ground state constants complete up to H constants including the K-dependent parameters A 0 , D K 0 , and H K 0 as obtained by the 6 Ϯ1 /2 6 Ϯ2 -6 Ϯ1 /2 6 ϯ2 loop method were determined by a merge of 2388 ground state combination differences with 59 rotational data. The v 3 ϭ 1 and v 6 ϭ 1 and 2 levels appear to be unperturbed intervibrationally for the J and K values that could be accessed. However, ⌬l ϭ ⌬k ϭ Ϯ2 and ⌬l ϭ Ϯ2, ⌬k ϭ ϯ4 interactions affect the v 6 ϭ 1 level while the v 6 ϭ 2 levels undergo three interactions of ⌬l ϭ ⌬k ϭ Ϯ2, ⌬l ϭ Ϯ2, ⌬k ϭ ϯ1 and ⌬l ϭ Ϯ4, ⌬k ϭ ϯ2 type. Typically, for the different bands, 2000 -4000 pieces of infrared data augmented by 36 -120 rotational data were fitted together. Owing to the weakness of the 2 6 band, the body of v 6 ϭ 2 data was enlarged by energies that are deduced from the 2 6 -6 and 6 bands and which span in particular high K values. Comparison with available ab initio data derived from the harmonic and anharmonic force fields is made.