Infrared spectra of the CF3I dimer: A concurrent application of matrix-isolation spectroscopy and cavity ring-down spectroscopy

Abstract

We have observed infrared spectra of the CF(3)I dimer produced in a supersonic jet by matrix-isolation Fourier transform infrared spectroscopy and infrared cavity ring-down (IR-CRD) spectroscopy. In the matrix-isolation experiments, the dimer was isolated in an Ar matrix by the pulse-deposition method. The recorded spectral range covers the symmetric (nu(1)) and doubly degenerate (nu(4)) C-F stretching regions. From the concentration dependence of the matrix-isolation spectra we have assigned one dimer band for each fundamental region. It was not easy to identify the dimer band for the nu(4) band because of the multiplet feature of the monomeric nu(4) band caused by the site symmetry breaking. The spectra of (CF(3)I)(2) in the nu(4) band region were thus also measured in the gas phase by IR-CRD spectroscopy, where we detected two dimer bands. Comparing the observed band positions with the results of quantum chemical calculations, we have assigned the observed dimer bands to the head-to-head isomer. The structure of (CF(3)I)(2) and its photochemical implications are discussed, in comparison with methyl iodide dimer reported previously [Ito et al., Chem. Phys. Lett. 343, 185 (2001)].

FT‐IR and FT‐Raman investigations of the chemosensing material para‐hexafluoroisopropanol aniline

“…2, the degenerate CF 3 deformation can be observed at 707 cm −1 and the band contour appears as C‐type band. According to vibrational wavenumber analysis of p ‐HFIPA (Table 1), the vibrational band at 702 cm −1 can be assigned as out‐of‐phase CF 3 bending vibration, which is similar to the previous observations on CF 3 deformations in CF 3 I molecule 38, 39. Although the infrared activity of ring torsion is quite weak, the Raman activity of ring torsion is relatively strong, which can be observed from the band at 645 cm −1 .…”

Infrared matrix-isolation spectroscopy of trifluoroacetic acid hydrates

“…An experimental setup for the matrix-isolation spectroscopy has been described elsewhere [24][25][26][27]. In brief, two types of premixed samples of TFA/H 2 O/Ar were prepared in a stainless steel vessel for the experiments.…”

“…Spectra thus obtained are analyzed with the aid of theoretical calculations to assign vibrational peaks for each of TFA-(H 2 O) n complexes, as has been done previously [24].…”

Switching the Spin State of Diphenylcarbene via Halogen Bonding

“…These donors were selected since they have been shown to form strong halogen bonds with various Lewis bases, − and in addition are small enough to diffuse in solid argon during annealing. Thus, warming a CF 3 I-doped argon matrix from 8 to 25 K results in the formation of van der Waals dimers . This ability to diffuse in solid argon is prerequisite for inducing bimolecular chemistry under the conditions of matrix isolation.…”

“…Thus, warming a CF 3 I-doped argon matrix from 8 to 25 K results in the formation of van der Waals dimers. 27 This ability to diffuse in solid argon is prerequisite for inducing bimolecular chemistry under the conditions of matrix isolation.…”