Photoionization of HCN: The Electron Affinity and Heat of Formation of CN

摘要

A rehyphen;examination of the photoionization of HCN has revealed two processes,HCNthinsp;plus;thinsp;hngr;rarr;Hthinsp;plus;thinsp;plus;CNminus;, andHCNthinsp;plus;thinsp;hngr;rarr;Hthinsp;plus;thinsp;plus;CNplus;e, not previously reported. The difference in threshold values for the two processes leads directly to the electron affinity for CN, 3.82thinsp;plusmn;thinsp;0.02 eV. The threshold for the second process leads toDgr;Hf0deg;lpar;CNrpar;thinsp;equals;thinsp;105.5thinsp;plusmn;thinsp;2kcalsol;mole, butDgr;Hfdeg;lpar;HCNrpar;remains a major source of uncertainty.