Eight undergraduates participated in the 2004 Summer Research Program in Chemistry. Researchers and their projects included:

Audra Fisher

Greeley, Colorado

Audra successfully synthesized the dione starting with 2-methylresorcinol (structures shown below.) The structure was established by MS, ¹H and ¹³C NMR and an exact mass determination at the University of California, Riverside. This tetrachloro dione is important to our research because it will be the first humic acid model tetrachloro dione examined in chlorination reactions with OCl^-, HOCl and the chloramines.

Heidi Forberg

Temecula, California

Heidi carried out molecular orbital calculations on cation intermediates from terminal alkenes with fluorine substituents. The fluorine atom is strongly electron-withdrawing, but it can stabilize positive charge on an alpha-carbon through backbonding resonance. These calculations are helping us choose model fluoroalkenes we will study with electrophiles like trifluoromethanesulfonic acid and chlorosulfonyl isocyanate, where carbocation intermediates are indicated.

Evan Miller

Atascadero, California

Evan completed our study on the reactions of the chloramines, monochloramine ( NH₂Cl) and dichloramine (NHCl₂), with phenols that are models of subsituents in the humic acids. Evan synthesized the N-chloroimine and quinone (structures shown below) and established that they are products of the reaction of m-cresol with the chloramines. An article describing this research has recently (October 1) been published in the journal of Environmental Science and Technology. Audra Fisher and Ashley Ramirez also contributed to this research, as did other former students, and are authors of the article. 

Sarah Wood

San Diego, California

Sarah has carried out a systematic study of the apparent "conformers" of the pentachloride of resorcinol (structure shown above.) We refer to them as "conformers" because we are uncertain of their exact relationship. One of the "conformers" shows the vinyl proton at 7.4 ppm and the other at 7.1 ppm. Sarah has developed synthetic procedures for consistently making both "conformers." She has established that both "conformers" equilibrate to the same mixture if allowed to stand in CDCl₃. Jeff Lehman, Department of Chemistry, Grossmont College, using molecular orbital calculations, because of the complexity, has failed to confirm theoretically that conformers exist for the pentachloride. Another troubling aspect is that the 300 MHz ¹³C NMR studies show only one carbonyl carbon is present for the 7.1 "conformer." This could result from the fact that both carbonyl carbons have the same chemical shift or that the two compounds are not "conformers". Sarah is now in the process of preparing very pure samples of each "conformer" for ¹³C NMR analysis on the 500 MHz NMR spectrometer at California State University, San Diego.

Nicole Acosta & Sean Rodriguez

Bakersfield, California & Imperial Beach, California

Nicole and Sean investigated the electrophilic reactions of trifluoromethanesulfonic acid with fluorosubstituted terminal alkenes. The regiochemistry, Markovnikov vs. anti-Markovnikov products, indicate where the charge is localized. These experimental data will be correlated with charge densities on the number-1 and number-2 carbons obtained from theoretical calculations of fluorosubstituted terminal alkenes.

Ashley Ramirez

Magalia, California

Among other research projects, Ashley examined the synthesis of dichloro lactam (structure shown below) from the pentachloride of resorcinol (structures shown below) and aqueous NH₂Cl at high pH, attempting to improve the yield. We discovered the lactam a few years ago but the yield was low (ca. 2%) and the structure was uncertain. (We were uncertain whether the vinyl chlorine was alpha or beta.) This past spring Dr. Larry Henling, crystallographic expert on the faculty of California Institute of Technology, and Dr. Stan Manatt of Jet Propulsion Laboratories absolutely established the structure as the one shown with the chlorine on the b-carbon. Ashley's investigations greatly improved the yield to 32% and established that the same yield was obtained from 25 mg as 500 mg of starting pentachloride.

Adam Bishop

Temecula, California

"Studies of the interaction of halobenzenes with water adlayer on a Al₂O₃ (0001) surface." Adam worked with a Westmont student Jonathan Brigham on this project under the joint direction of Ken Martin and Dr. Allan Nishimua (Chair of Chemistry, Westmont College). Alternating layers of various dihalobenzenes and water were deposited on an inert solid substrate surface. The thickness of the layers varied from thin films to layer only a few monolayers thick. The interactions of the two chemically different layers were monitored by measured desorption temperature in an ultra high vacuum (UHV) chamber. The study revealed the formation of some surprising halobenzene/water clusters. The results will be reported at the upcoming meeting of the Western Spectroscopy Association Conference.