Resumen de Cl2O4 in the Stratosphere:: A Collaborative Computational Physical Chemistry Project
Lisa Lever, Jerry Howe, David M. Whisnant
Computational software is moving into the chemistry mainstream and should be introduced into the undergraduate curriculum. This paper describes a collaborative computational project involving the implications of Cl2O4 for the stratospheric degradation of ozone. The project would be appropriate for physical chemistry, advanced inorganic chemistry, and an upper-level integrated laboratory or environmental chemistry course. After an initial WWW search for information on stratospheric ozone, students use group theory, IR and Raman spectra data from the literature, and formal charges to determine the most likely structure of Cl2O4. They then use pooled results of RHF calculations with different basis sets to study the effect of changing basis sets on ab initio calculations of the structure of this molecule. In the next phase of the project, the students pool results of MP2/6-31G(d) level calculations to predict the spontaneity of a possible ozone-destroying reaction. In the last phase, they engage in an online discussion of the kinetics of a potential mechanism for which this reaction is one step. Calculations in this project were done with Gaussian 98W on 266- and 450-MHz Pentium II PCs. Communication during the project was primarily by electronic mail and the WWW.
