1. 20 th Biennial Conference on Chemical Education Indiana University, Bloomington, Indiana, July 27, 2008

2. Solving Qualitative Organic Problems with the Aid of an Automated Isotope-Pattern Analyzer Ray A. Gross, Jr. Prince George’s Community College

3. Introduction Many aryl compounds contain small combinations of Br, Cl and S atoms. The Br, Cl, S stoichiometry of most of these compounds is revealed in their characteristic molecular-ion peaks in their low-resolution mass spectra An automated isotope-pattern analyzer has been developed that determines the A + 2 composition of these compounds.

4. Outline Three qual-organic problems will be solved with the aid of the IPA. The IPA will be demonstrated.

5. Problem 1 What is the Br, Cl, S composition? Spectrum: Spectral Database for Organic Compounds, SDBS

6. Problem 1 What is the Br, Cl, S composition? M = 288 (11.5%) M + 2 = 290 (8.5%) M + 4 = 292 (2.0%) Spectrum: Spectral Database for Organic Compounds, SDBS

8. 3,4-toluenedisulfonyl dichloride

9. Problem 2 Compound A: mp 82 o C m/e % 19449.4 19510.4 19647.0 1975.8 19816.1 1991.2 2001.6 2010.1

10. Compound A: Cl 3

11. Compound A: 2,4,6-trichlorotoluene

12. Problem 3

13. Compound A: Cl 3 S 1

14. Compound B: Cl 2 S 1

15. Compound A: 2,4-dichlorobenzenesulfonyl chloride

16. Conclusion The IPA is a useful tool for qualitative organic analysis. Finds A + 2 compositions for 21 combinations of Br, Cl and S. J. Chem Educ., 2007 84, 987-991