Determination of nuclear spin–rotation coupling constants in CF3I by chirped-pulse Fourier-transform microwave spectroscopy

The halogen bond between ethene and a simple perfluoroiodoalkane: C2H4⋯ICF3 identified by broadband rotational spectroscopy

“…The value for v aa (I) of the isolated CF 3 I monomer [11] is À2145.017(11) MHz. If the charge distribution at iodine is not affected by complexation, the value for v aa (I) in a complex must necessarily be less than that in an isolated monomer of CF 3 I.…”

“…A comprehensive description of the CP-FTMW spectrometer [11] is provided in a recent work and only a brief description is given here. An arbitrary waveform generator (Tektronix, AWG7102B) is used for the initial generation of a chirped microwave pulse that sweeps from 0.5-12 GHz over a period of 1 ls.…”

A Ka-band chirped-pulse Fourier transform microwave spectrometer

“…The cavity FTMW spectrometers are also well suited to limited search applications where an accurate prediction of the spectrum for the species of interest is available. During the past few years, the applications of chirped-pulse spectroscopy have been numerous, including the study of metal-containing molecules [3][4][5][6], conformationally rich molecules [7], and molecular clusters [8]. Chirped-pulse instruments have also been developed to work over reduced bandwidths and at low frequency [9,10].…”

High resolution investigation of the v3 band of trifluoromethyliodide (CF3I)

“…Because of the existence of a non-zero nuclear spin for the iodine nucleus (I = 5/2), each rotational level of CF 3 I is split into six sublevels designated by the F quantum number (F = J ± 1/2, J ± 3/2 or J ± 5/2, with F > 0). This quadrupole hyperfine structure is easily observable by microwave techniques in the ground state [1,2,4], and in the 3 1 and 6 1 vibrational states [2,3]. Usually, this hyperfine structure gives rise to an increase of the apparent linewidth in infrared spectra [8].…”

“…It has three symmetric vibrations (type A 1 ) and three degenerate (type E) normal vibrations, which are described shortly in Table 1. This molecule was the subject of numerous spectroscopic studies using microwave [1][2][3][4], infrared (Fourier transform or tunable diode laser) [5][6][7][8][9][10][11][12][13], Infrared-Microwave Double Resonance [14], infrared radio frequency double resonance [15], laser microwave double resonance [16], Lamb dip spectroscopy [17], Raman [18,19], or electron diffraction spectroscopy [20] techniques. This molecule was also the subject of harmonic force field calculations [21].…”