Dissociative Photoionization and Thermochemistry of Dihalomethane Compounds Studied by Threshold Photoelectron Photoion Coincidence Spectroscopy

Autor:	Andras Bodi, James P. Kercher, D. Wurzelmann, B. Miller, Alexsandre F. Lago, Tomas Baer, Bálint Sztáray
Rok vydání:	2005
Předmět:	Chemistry Ionization Analytical chemistry Thermochemistry Molecule Photoelectron photoion coincidence spectroscopy Photoionization Physical and Theoretical Chemistry Bond-dissociation energy Dissociation (chemistry) Standard enthalpy of formation
Zdroj:	The Journal of Physical Chemistry A. 109:1802-1809
ISSN:	1520-5215 1089-5639
Popis:	The dissociative photoionization studies have been performed for a set of dihalomethane CH(2)XY (X,Y = Cl, Br, and I) molecules employing the threshold photoelectron photoion coincidence (TPEPICO) technique. Accurate dissociation onsets for the first and second dissociation limits have been recorded in the 10-13 eV energy range, and ionization potentials have been measured for these compounds. By using our experimental dissociation onsets and the known heat of formation of CH(2)Cl(2) molecule, it has been possible to derive the 0 and 298 K heats of formation of all six neutral dihalomethanes as well as their ionic fragments, CH(2)Cl(+), CH(2)Br(+), and CH(2)I(+), to a precision better than 3 kJ/mol. These new measurements serve to fill the lack of reliable experimental thermochemical information on these molecules, correct the old literature values by up to 19 kJ/mol, and reduce their uncertainties. From our thermochemical results it has also been possible to derive a consistent set of bond dissociation energies for the dihalomethanes.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::469f98809d71e49697b283e93adec779 https://doi.org/10.1021/jp045337s Zobrazit plný text záznamu