Ion imaging study of IO radical photodissociation: Accurate bond dissociation energy determination
نویسندگان
چکیده
0009-2614/$ see front matter 2008 Elsevier B.V. A doi:10.1016/j.cplett.2008.04.009 * Corresponding author. Fax: +1 979 845 2971. E-mail address: [email protected] (S.W. North). We have studied the photodissociation dynamics of expansion-cooled IO radicals at 454.9 nm, corresponding to the AP3/2–XP3/2 (1–0) bandhead, using velocity map ion imaging. The radicals were generated using a late-mixing dual-valve photolytic reactor source. Analysis of the I(P3/2) photofragment speed distribution provides a direct determination of the ground state bond energy of D0ðIOÞ = 54:9 þ0:2 0:4 kcal/mol and a heat of formation 298 K of DH 298 f ðIOÞ = 29:2 þ0:4 0:2 kcal/mol. 2008 Elsevier B.V. All rights reserved.
منابع مشابه
Photodissociation of the BrO radical using velocity map ion imaging: excited state dynamics and accurate D0(0)(BrO) evaluation.
We have studied the photodissociation dynamics of expansion-cooled BrO radical both above (278-281.5 nm) and below (355 nm) the A (2)Pi(3/2) state threshold using velocity map ion imaging. A recently developed late-mixing flash pyrolytic reactor source was utilized to generate an intense BrO radical molecular beam. The relative electronic product branching ratios at 355 nm and from 278 to 281.5...
متن کاملDirect observation of the primary and secondary C-Br bond cleavages from the 1,2-dibromopropane photodissociation at 234 and 265 nm using the velocity map ion imaging technique.
Photodissociation dynamics of 1,2-dibromopropane has been investigated at 234 and 265 nm by using the velocity map ion imaging method. At both pump energies, a single Gaussian-shaped speed distribution is observed for the Br*((2)P(1/2)) fragment, whereas at least three velocity components are found to be existent for the Br((2)P(3/2)) product. The secondary C-Br bond cleavage of the bromopropyl...
متن کاملEnergy partitioning following photodissociation of methyl iodide in the A band: A velocity mapping study
Translational and internal energy partitioning in the methyl and iodine fragments formed from photodissociation of methyl iodide in the A-band region is measured using velocity mapping. State-selective detection combined with the very good image quality afforded by the two-dimensional imaging technique allow a detailed analysis of the kinetic energy and angular distributions. Product vibrationa...
متن کاملDetermination of the barrier height for acetyl radical dissociation from acetyl chloride photodissociation at 235 nm using velocity map imaging.
This work uses velocity map imaging to determine the barrier height for acetyl radical, CH3CO, dissociation to CH3 + CO. Photodissociation of acetyl chloride at 235 nm generates acetyl radicals with an internal energy distribution spanning this barrier. We determine the velocity and internal energy distribution of all nascent acetyl radicals, stable and unstable, by measuring the velocities of ...
متن کاملPhotodissociation dynamics of thiophenol-d1: the nature of excited electronic states along the S-D bond dissociation coordinate.
The S-D bond dissociation dynamics of thiophenol-d1 (C6H5SD) pumped at 266, 243, and 224 nm are examined using the velocity map ion imaging technique. At both 266 and 243 nm, distinct peaks associated with X and A states of the phenylthiyl radical (C6H5S*) are observed in the D+ image at high and low kinetic energy regions, respectively. The partitioning of the available energy into the vibrati...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008