Study of thev4= 2 andv4= 3 States of PF3by High Resolution Infrared Spectroscopy

The v4=1 and v4=2 rovibrational levels of PF3 revisited: New solutions for old topics

“…The 2 4 2 perpendicular band was, as stressed by the authors, not visible in the spectrum they had at their disposal. However, Badaoui et al [10] used in their least-squares calculations 249 energies of the 2 -2 sublevel, deduced from observed 21 44 2   hot transitions and the corresponding energies of the v 4 =1 level from the previous study [5]. The results of the least-squares calculations performed on the experimental data for the v 4 =2 level were regarded as being satisfactory by the authors, even though "heavily biased in favor of v 4 =2 0 , for which roughly six times more data were present" (1166 data for 0 4 2 , 198 for 2 4 2  and none for 2 4 2  ).…”

“…In the meantime, Badaoui et al [10] studied in 1997 for the first time with high-resolution the v 4 =2 and v 4 =3 states. These authors pointed out the difficulty of analyzing the v 4 =2 level, for which only the 2 0 sublevel is reached by overtone 0 4 2 transitions with non-vanishing intensities.…”

High-resolution FTIR and MMW study of the v4=2 (A1,E) excited state of 14NF3 near 985cm−1: the axial ground state rotational constants derived by the “loop-method”

“…The last three equations relative to Dc B ll have the same behaviour: Eqs. (16) and (18) To summarize, a majority (12 over 18) of the tried relations of equivalence seem to semi-quantitatively support the validity of the theory for an isolated v t = 2 state, but the invariance relations are less satisfactorily fulfilled than for the v 4 = 1 state. The principal reason, is the smaller amount of data which did not allow us to determine the H sextic terms, as well as the s terms, and did not give any information about the small l (2, À4) and k(0, 6) splittings, which had to be neglected.…”

“…To compare the v 4 = 2 states of the 14 NF 3 and PF 3 [16] congener molecules, we reported in Table 5 the main parameters of both molecules. We note a general decrease of the absolute value of the parameters from 14 NF 3 to PF 3 and only a B has an opposite sign.…”

A new analysis of the ν4(E) rovibrational band of the symmetric top molecule PF3

“…It has four vibrational normal modes: two non-degenerate A 1 -type modes: m 1 and m 2 ; two degenerate E-type modes: m 3 and m 4 . PF 3 was the subject of several studies by rotational and vibrational spectroscopy [1][2][3][4][5][6][7][8][9]. The more recent ones can be summarised as:…”