Table of Contents
Laser Chemistry
Volume 3, Issue 1-6, Pages 215-222

Application of Photoacoustic Calorimetry to the Photofragmentation of Cr(CO)6

Department of Chemistry, Harvard University, Cambridge 02138, Massachusetts, USA

Copyright © 1983 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Photolysis of Cr(CO)6 in cyclohexane yields solvated pentacarbonyl species within 25 ps. Using high-speed photoacoustic calorimetry, we have determined the heat of reaction for this photofragmentation, directly measuring the energy required to break a single metal–carbonyl bond followed by solvation of the fragments. The energy required to photochemically dissociate a single CO in cyclohexane exceeds the gas phase average bond dissociation energy by at least 11 kcal/mol. However, the determined heat of reaction agrees well with the activation energies derived from thermal decomposition kinetics.