HeI 2 (B,19,n B ) complexes and He 2 I 2 (B,19,n B ) clusters in Fig. 6.37. The band displaced * 30 cm
−1 to the short wavelength side (m 1 = 17830.4 cm
−1 ) can correspond to the N 2 I 2 (B,19,n B ) complexes [125]. To check this assumption, we
measured the excitation spectrum of luminescence in the UV spectral range in the
m 2 = 23300-23500 cm
−1 spectral range at m 1 = 17830.4 cm
−1 . We found some
strong bands in the spectrum. Then we measured an action spectrum at one of the
bands of the excitation spectrum (Fig. 6.37). The positions of the
m 1 = 17830.4 cm
−1 band are the same in both spectra given in the figure, and this
band has to be assigned to the N 2 I 2 (B,19,n B ) complex. All the following measurements were carried out at m 1 = 17830.4 cm
−1 .
Survey excitation spectrum of luminescence in the UV spectral range, k lum
2600–3800 Å at m 1 = 17830.4 cm
−1 measured at the He + N 2 mixture is presented
in Fig. 6.38.
The N 2 I 2 (E,v E ,n E ← B,19,n B ) bands are fitted into several progressions. The
most long-wavelength one, N 2 I 2 (E,v E = 0,n E ← B,19,n B ), consists of 5, n E = 0–4,
bands. The energy gaps between the first n E = 0, terms, corresponding to the
v E = 0, 1, has to be close to that of I 2 (E,v E = 0,1), * 101 cm
−1 , and weak bands of
the N 2 I 2 (E,v E = 1, n E = 0,1 ← B,19,n B ) transition, m 2 % 23461 and 23498.8 cm
−1 ,
is overlapped with strong N 2 I 2 (E,v E = 0,n E = 3,4 ← B,19,n B ) and I 2 (b,1 ← B,15)
bands.
Fig. 6.37 Excitation spectra of luminescence of the I 2 (B,19) and products of VP of the
N 2 I 2 (B,19), T-shaped, free-rotor HeI 2 (B,19) complexes and He 2 I 2 (B,19) cluster (upper curve) and
action spectra measured at the m 2 = 23469.64 cm
−1 band, see Fig. 6.38 (lower curve) [126]
(Reprinted from Chemical Physics Letters, Vol. 714, V.V. Baturo, R. Kevorkyants, S.S. Lukashov,
S.S. Onishcenko, S.A. Poretsky, A.M. Pravilov, The valence and ion-pair states of the N 2 I 2 van der
Waals complex. p.p. 213-218 (2019) with permission from Elsevier)
248
6 Weakly-Bound Complexes and Clusters
−1 to the short wavelength side (m 1 = 17830.4 cm
−1 ) can correspond to the N 2 I 2 (B,19,n B ) complexes [125]. To check this assumption, we
measured the excitation spectrum of luminescence in the UV spectral range in the
m 2 = 23300-23500 cm
−1 spectral range at m 1 = 17830.4 cm
−1 . We found some
strong bands in the spectrum. Then we measured an action spectrum at one of the
bands of the excitation spectrum (Fig. 6.37). The positions of the
m 1 = 17830.4 cm
−1 band are the same in both spectra given in the figure, and this
band has to be assigned to the N 2 I 2 (B,19,n B ) complex. All the following measurements were carried out at m 1 = 17830.4 cm
−1 .
Survey excitation spectrum of luminescence in the UV spectral range, k lum
2600–3800 Å at m 1 = 17830.4 cm
−1 measured at the He + N 2 mixture is presented
in Fig. 6.38.
The N 2 I 2 (E,v E ,n E ← B,19,n B ) bands are fitted into several progressions. The
most long-wavelength one, N 2 I 2 (E,v E = 0,n E ← B,19,n B ), consists of 5, n E = 0–4,
bands. The energy gaps between the first n E = 0, terms, corresponding to the
v E = 0, 1, has to be close to that of I 2 (E,v E = 0,1), * 101 cm
−1 , and weak bands of
the N 2 I 2 (E,v E = 1, n E = 0,1 ← B,19,n B ) transition, m 2 % 23461 and 23498.8 cm
−1 ,
is overlapped with strong N 2 I 2 (E,v E = 0,n E = 3,4 ← B,19,n B ) and I 2 (b,1 ← B,15)
bands.
Fig. 6.37 Excitation spectra of luminescence of the I 2 (B,19) and products of VP of the
N 2 I 2 (B,19), T-shaped, free-rotor HeI 2 (B,19) complexes and He 2 I 2 (B,19) cluster (upper curve) and
action spectra measured at the m 2 = 23469.64 cm
−1 band, see Fig. 6.38 (lower curve) [126]
(Reprinted from Chemical Physics Letters, Vol. 714, V.V. Baturo, R. Kevorkyants, S.S. Lukashov,
S.S. Onishcenko, S.A. Poretsky, A.M. Pravilov, The valence and ion-pair states of the N 2 I 2 van der
Waals complex. p.p. 213-218 (2019) with permission from Elsevier)
248
6 Weakly-Bound Complexes and Clusters