Observation of the ν1 OH(OD) stretch of HOI and DOI by Fourier transform infrared emission spectroscopy

Abstract

The spectra of vibrationally hot HOI formed in the reaction of alkyl iodides with oxygen atoms are observed by Fourier transform infrared emission spectroscopy. The v=1–3 levels of the OH stretch are observed via the Δv=−1 and Δv=−2 sequence bands. The spectrum of DOI is observed by using 2,2,2-d3-iodoethane as the precursor in the oxygen atom reaction. The v=1–4 levels of the OD stretch are observed in the Δv=−1 sequence band, and the v=1–5 levels of the OD stretch are observed in Δv=−2. Medium resolution spectra (0.031 cm−1 apodized) are recorded and rotationally analyzed for the ν1 fundamental and 2ν1−ν1 hot band of HOI. An estimate of the HOI ground state structure is made by constraining the OH bond length to its value for HOCl and HOBr and calculating the HOI bond angle and the OI bond length by least squares fit to the ground state rotational constants.

298 K rate coefficients for the reaction of OH with <i>i</i> - C<sub>3</sub>H<sub>7</sub>I, <i>n</i> - C<sub>3</sub>H<sub>7</sub>I and C<sub>3</sub>H<sub>8</sub>

“…As i−C 3 H 7 I and (by analogy) n−C 3 H 7 I react rapidly with O( 3 P) (Gilles et al, 1996), it is necessary to assess the potential impact of this on the reported rate constants. The products of the reaction of O( 3 P) with the iodo-propanes are IO, HOI, C 3 H 6 , and C 3 H 7 (Klaasen et al, 1996). By analogy with the reaction of O( 3 P + C 2 H 5 I (Monks et al, 1995) reaction (14a) is expected to dominate with a branching ratio close to 0.9.…”

Experimental and Computational Investigations of the Reaction of OH with CF3I and the Enthalpy of Formation of HOI

“…As can be seen from Table 2, there is good agreement with the observed frequencies of the reactants and products. 5,29 Single-point high-level calculations were then carried out at the stationary points to characterize their energy, and these data are listed in Table 3. These are frozen-core, all-electron calculations without effective core potentials.…”

“…Finally, the kinetic measurements are combined with ab initio information about the potential energy surface to obtain the thermochemistry of a dominant product, hypoiodous acid. HOI is a major product of the reaction of ground-state atomic oxygen with C 2 H 5 I and larger iodoalkanes 4,5 and recently has been studied by photoionization 6 and FT-IR emission techniques. 7 ∆ f H 298 (HOI) has not previously been determined experimentally, despite its importance in understanding the photodissociation dynamics 8 and photoionization 6 of hypohalous acids and the roles of HOI in the mechanisms of iodine-mediated flame suppression 9 and stratospheric iodine chemistry.…”

Full-dimensional analytical ab initio potential energy surface of the ground state of HOI

“…15 Of these works, it is relevant to emphasize the high resolution study of the OH stretch of HOI done by Klaassen et al, 14 which resulted in an estimate of geometrical and vibrational parameters, and the accurate geometry and harmonic force field determination conducted by Ozeki and Saito. 15 In this study, we present a full-dimensional analytical PES obtained from ab initio data calculated using multiconfigurational wavefunctions, with the inclusion of relativistic effects, capable of describing the main features of the [H, O, I] system within chemical accuracy.…”

“…tance of a water molecule through CCSD(T)//B3LYP calculations [CCSD(T): coupled-cluster with single double and perturbative triple excitations]; and an extensive investigation of the kinetics of several iodine compounds was conducted by Canneaux et al 10 Experimentally, since the first spectroscopic studies by Ogilvie et al, 11 several investigations on the rovibrational spectra of hypoiodous acid were carried out, [12][13][14] as well as an observation of the pure rotational spectrum of HOI. 15 Of these works, it is relevant to emphasize the high resolution study of the OH stretch of HOI done by Klaassen et al, 14 which resulted in an estimate of geometrical and vibrational parameters, and the accurate geometry and harmonic force field determination conducted by Ozeki and Saito.…”