| Chemistry Students Develop, Test, and Compare Molecules
It's 1:00 pm, and Emily Flether and Say-Lee Teh have been working in the chemistry lab for more than 3 hours to complete a chemical comparative analysis that will compare the chemical properties of cobalt, rhodium, and iridium. Emily and Say-Lee have been working on one of 12 research projects with Dr. Lee Roecker, a chemistry professor here at Berea, for eight weeks to gather data on three elements, only two of which were successful, in order to make a presentation on the similarities between cobalt and its periodic table neighbors rhodium and iridium.
Emily and Say-Lee put in hard hours in the lab.
The ladies have been working all summer to create the elements to reach conclusions for a comparative analysis. Emily and Say-Lee began their summer research at the beginning of June by studying cobalt complexes, which is cobalt that has 6 bonds attached, that were made in previous years by Dr. Lee Roecker’s summer research students.
Once they were familiar with the cobalt, the pair was ready to develop their own samples of rhodium and iridium to bond to ligand molecules. A ligand is a large organic molecule that bonds by chemical reaction to a specific site on another molecule.
The process for making a ligand includes reacting a number of chemicals by heating them and then crystallizing to purify the molecule. Once the crystals fall through the solution, they are re-crystallized to ensure that what the two ladies needed was included in the molecule. Emily and Say-Lee then utilized the NMR, nuclear magnetic resonant, machine.
The NMR is a complicated machine that excites the molecules by spinning them to give an electric charge and then measures the amount of time it takes for the molecule to return to its original state. Once this process is complete, the NMR produces a graph that the ladies were then able to analyze to be sure that the ligand molecule was indeed made. Once they were sure, Emily and Say-Lee made a stock of these ligand molecules that they used for the remainder of the experiment.
Once the ligands were formed, they reacted the molecules with cobalt, rhodium and iridium for a long period of time. While cobalt reacted in about one day, the rhodium took almost a week, and the iridium took more than a month for a small amount of sample to form.
Once the molecules of cobalt, iridium, and rhodium had developed, Emily and Say-Lee had to purify the product through a sufodex column, which is an ion exchange resin. This long, difficult process involved running various solutions with varying molarities through a column filled with both the product and the solutions in order to separate materials that were necessary from the ones that were not. Once the product was separated and gathered, the pair had to run it through the UV Vis, which allowed them to test the concentration using light waves from the color spectrum. Once the product was confirmed, it had to be solidified. The girls began the long process of waiting for the crystals to fall out of the solution. This is where iridium failed.
With only two elements left, Say-Lee and Emily proceeded to run the samples through the Mass Spectrometer. The Mass Spec was acquired by $230,000 from the National Science Foundation's (NSF) in June of 2004. Associate professor of the chemistry department, Dr. Matthew Saderholm applied for the grant from the National Science Foundation's (NSF) Major Research Instrumentation (MRI) grant program in January 2004.
The mass spec process brought the project to a close, and the ladies were then able to begin comparing the results and compiling their research into a paper and poster presentation.
For Emily, a senior chemistry major, this research has given her a familiarity with chemistry that she will continue to use. “I have two advanced labs, so I’m going to be doing a lot of chemistry. I’m more familiar with where things are and I learned a lot about the different machines that we used,” she comments. The research has also helped Emily realize that a career in chemical research may not be for her. “Well, I think I’ve learned that I do like chemistry, but I’m not sure that I want to work in a lab for the rest of my life. I’d like to continue because it’s interesting, but sitting in a lab for 8 hours a day for the rest of my life isn’t where I want to be,” she says.
While the project itself may seem like the most difficult part of the experience, Emily and Say-Lee find the biggest challenge to be the looming paper and presentation that will come in a few months. Say-Lee elaborates, “You know that you have to do a paper, and you kind of struggle because you have to know everything about it. You have to go back and see why this thing happened and you have to organize it and get yourself to understand the way it’s supposed to be, so when you tell people you will be much more confident. Especially when you go to the conference there will be people asking you a lot of questions, and you need to prepare.” Emily adds, “Its always in the back of our minds, ‘oh my gosh I really have to know what’s going on here, cause someone is going to ask me a really off-the-wall question and I’m going to have to know the answer.’”
Despite the challenge of writing a paper and presenting a poster, Emily and Say-Lee know that the experience has been memorable, and full of rewarding surprises. Emily says, “I’m surprised at how much I actually learned, I just thought I would be here and be told what to do, but I can actually figure things out for myself now. I think being able to be more independent in the lab, also has surprised me; being able to have directions given to me and being able to do it.”
In all, Say-Lee and Emily say that they have had a wonderful experience, and have worked well together. In the beginning there were some stressful moments. Say-Lee explains, “In the beginning she was working with iridium and I was doing rhodium and I don’t know what she did, but everything came out right for her, and everything I did wouldn’t work. You have stress when your partner gets something better and you feel really challenged because you try to get your stuff to go really well. You tend to draw comparisons.” Throughout the experiment, there were challenges, but when one element was not successful, Emily and Say-Lee felt disappointed. “I want my iridium to work so bad and all her rhodium is so good. Yeah it would’ve been great if I would talk about iridium and she could talk about rhodium, but iridium didn’t work so now we have to split it up.”
At the conclusion of the project, the girls hope to be able to draw clean comparisons, not between themselves, but between the cobalt and rhodium, and to send Dr. Roecker from Berea with an exciting last research project. “He [Roecker] was very patient with us this summer. It’d be nice to give him something really cool, to go out with a bang,” says Emily. Dr. Roecker will be leaving Berea to join his wife in Chicago