The moment had arrived -- the moment that we would each be expected to submit an 8-12 page paper and a group presentation documenting our research over the Interim period. When I first received the assignment, it really didn't seem that daunting or challenging. I served as an intern to the Department of Energy over the summer, which required a 5000-word professional publication with at least fifteen references and a 10-minute presentation in front of the entire program. After that experience, I was confident that I could tackle any project thrown my way in record time.
Which is why I procrastinated until the night before to start my research paper. Bad idea.
The issue was not writing the paper. I easily reached the 8-12 page minimum a few hours after I started. The problem was getting all my information into the paper, along with appropriate images and citations. That process took me most of the next day.
It resulted in 19 pages, excluding the title page and references. Yeah. Over-achiever. But it was a really good paper.
The presentation process lasted only about half the time, which was fortunate. I am now running through my presentation notes so that I can provide good information to my audience tomorrow morning.
Maybe I'll post a link to my paper and presentation later.
Wish me luck!
Tuesday, January 29, 2013
Friday, January 25, 2013
Day Sixteen: Everything That Could Go Wrong
It probably didn't help that the sleet started to fall on my uncovered head as I walked to Milliken this morning.
On the other hand, I had a voucher for free coffee and ordered a large one. The Pop-Tart and Oreos were good, too.
Anyways.
I was feeling quite productive as I wandered into the laboratory this morning, having set my large coffee in the hallway where it would be protected from chemicals. I quickly spotted three TLC plates with samplings of my thirty-five test tubes from yesterday and prepared a new solvent chamber to develop them while I drank my coffee. Unfortunately, things don't always go according to plan. The solvent touched my samples immediately instead of gradually in the absorbance process, and the plate was left in the chamber for too long, rendering the test useless.
However, all was not lost, as I realized that I wanted to test a larger sampling of my test tubes and prepared a new set of TLC plates: one for the original, and then four sets of every three. They developed uniformly and displayed great results under the UV light. I happily documented my results in my notebook.
Everything went downhill from there.
Dr. Bass and I decided that we would attempt to oxidize my impure 2-benzylcyclohexanol product and see what results we could get. So while my TLC plates were developing, I scrounged through his old laboratory for a three-necked flask, West condenser, separatory funnel, and thermometer adapter that would be the appropriate side for about 15 mL of reagents. The final apparatus was actually quite adorable:
The unfortunate part occurred when the supposedly half-hour reaction took an hour and a half to complete. And when I had to constantly adjust the heat setting to maintain a warm temperature. And when I left an important TLC plate in the chamber for too long.
Yeah. That's how the day ended. We can only hope that Monday will be more successful. There is still a distillation to complete.
Have a wonderful weekend!
On the other hand, I had a voucher for free coffee and ordered a large one. The Pop-Tart and Oreos were good, too.
Anyways.
I was feeling quite productive as I wandered into the laboratory this morning, having set my large coffee in the hallway where it would be protected from chemicals. I quickly spotted three TLC plates with samplings of my thirty-five test tubes from yesterday and prepared a new solvent chamber to develop them while I drank my coffee. Unfortunately, things don't always go according to plan. The solvent touched my samples immediately instead of gradually in the absorbance process, and the plate was left in the chamber for too long, rendering the test useless.
However, all was not lost, as I realized that I wanted to test a larger sampling of my test tubes and prepared a new set of TLC plates: one for the original, and then four sets of every three. They developed uniformly and displayed great results under the UV light. I happily documented my results in my notebook.
Everything went downhill from there.
Dr. Bass and I decided that we would attempt to oxidize my impure 2-benzylcyclohexanol product and see what results we could get. So while my TLC plates were developing, I scrounged through his old laboratory for a three-necked flask, West condenser, separatory funnel, and thermometer adapter that would be the appropriate side for about 15 mL of reagents. The final apparatus was actually quite adorable:
The unfortunate part occurred when the supposedly half-hour reaction took an hour and a half to complete. And when I had to constantly adjust the heat setting to maintain a warm temperature. And when I left an important TLC plate in the chamber for too long.
Yeah. That's how the day ended. We can only hope that Monday will be more successful. There is still a distillation to complete.
Have a wonderful weekend!
Thursday, January 24, 2013
Day Fifteen: Chromatography
It is at this point in the process, with Interim swiftly coming to a close, that I should say our polymerization will not be happening by the end of the month. There is a good chance that my colleagues will be able to continue their syntheses over the next semester, but since I will be studying abroad, I won't get to complete it myself.
In light of these developments, we spent today learning useful separation techniques in an attempt to isolate our products from the Grignard reaction. The first technique we explored was thin-layer chromatography (TLC). Essentially, a plastic-backed paper is coated with a polar compound - in this case, a silicon oxide. A drop of product is placed about one centimeter from the bottom of the paper, and the paper is set in a container with a small amount of solvent. This solvent is absorbed onto the TLC paper and catches the drop of product as it travels. Depending on the attractions between the solvent and the product, the product will move a certain distance along the paper, until the paper overcomes that attraction. If multiple components exist in the solution, they will separate based on their polarities. Analysis of the TLC is possible using UV radiation (if the product contains pi bonds) or solid iodine.
The purpose of the TLC was to determine what composition of solvent would best serve to separate our compounds in the product solution. In my case, I was attempting to separate 2-benzylcyclohexanol, some 2-chlorocyclohexanol, and a small amount of bibenzyl. Out of some varied combinations of hexane (nonpolar) and ethyl acetate (fairly polar), we determined that a 4:1 ratio was optimal overall.
The second technique we utilized was column chromatography. Assembling the column itself was probably the most interesting part of the process. First, we stuffed the bottom of the column right above the stopcock with a swab of cotton and poured in about 3 cm of hexane. Next, we measured enough silica gel powder to fill 20 cm of the column, dissolved it in hexane, and poured it into the column with excess hexane. After draining out the hexane and removing any air bubbles by tapping the column with a rubber hose, I poured a sample of my product dissolved in hexane and ethyl acetate into the column and let it settle into the silica layer. After that, it was a matter of preparing 50-mL hexane and ethyl acetate solvents of varying compositions - lower to higher concentrations of ethyl acetate.
We let the liquid elute for almost two hours, catching 5-10 mL at a time in test tubes and replacing the solvent when necessary. I tested for eluting product by placing small dots on TLC paper but not developing it, rather relying on UV radiation to confirm the presence of a benzyl product. There was no visible dot left by the end of the column chromatography process.
In the morning, I will develop TLC plates for every fourth test tube out of a total thirty-five and run appropriate gas chromatography samples from today's separation.
In light of these developments, we spent today learning useful separation techniques in an attempt to isolate our products from the Grignard reaction. The first technique we explored was thin-layer chromatography (TLC). Essentially, a plastic-backed paper is coated with a polar compound - in this case, a silicon oxide. A drop of product is placed about one centimeter from the bottom of the paper, and the paper is set in a container with a small amount of solvent. This solvent is absorbed onto the TLC paper and catches the drop of product as it travels. Depending on the attractions between the solvent and the product, the product will move a certain distance along the paper, until the paper overcomes that attraction. If multiple components exist in the solution, they will separate based on their polarities. Analysis of the TLC is possible using UV radiation (if the product contains pi bonds) or solid iodine.
The purpose of the TLC was to determine what composition of solvent would best serve to separate our compounds in the product solution. In my case, I was attempting to separate 2-benzylcyclohexanol, some 2-chlorocyclohexanol, and a small amount of bibenzyl. Out of some varied combinations of hexane (nonpolar) and ethyl acetate (fairly polar), we determined that a 4:1 ratio was optimal overall.
The second technique we utilized was column chromatography. Assembling the column itself was probably the most interesting part of the process. First, we stuffed the bottom of the column right above the stopcock with a swab of cotton and poured in about 3 cm of hexane. Next, we measured enough silica gel powder to fill 20 cm of the column, dissolved it in hexane, and poured it into the column with excess hexane. After draining out the hexane and removing any air bubbles by tapping the column with a rubber hose, I poured a sample of my product dissolved in hexane and ethyl acetate into the column and let it settle into the silica layer. After that, it was a matter of preparing 50-mL hexane and ethyl acetate solvents of varying compositions - lower to higher concentrations of ethyl acetate.
We let the liquid elute for almost two hours, catching 5-10 mL at a time in test tubes and replacing the solvent when necessary. I tested for eluting product by placing small dots on TLC paper but not developing it, rather relying on UV radiation to confirm the presence of a benzyl product. There was no visible dot left by the end of the column chromatography process.
In the morning, I will develop TLC plates for every fourth test tube out of a total thirty-five and run appropriate gas chromatography samples from today's separation.
Wednesday, January 23, 2013
Days Thirteen and Fourteen: Where's the Product?
It has been a long two days of IR, GC, NMR, and attempting to isolate our desired first product from unreacted materials still in solution. Thus far, it's been somewhat unsuccessful. Although it's clear from the spectra that 2-benzylcyclohexanol is in high abundance in my product solution, we haven't been able to purify it by vacuum distillation and aren't sure that we'll be able to perform the oxidation reaction as is. Tomorrow, we plan to use TLC spotting and column chromatography in a last shot at obtaining pure product prior to oxidation.
Unfortunately, this setback means that none of our monomers will be ready in time to polymerize at College of Charleston, which has been the source of some tension. I'm trying to remind myself that, in the real world, there isn't really a time-limit on research - even with the pressure to submit papers for certain journals and symposiums with deadlines - so I shouldn't be worried that three weeks of experimental work didn't yield the results that we had hoped for.
I expect that my group will have its work cut out for us during the upcoming semester.
Unfortunately, this setback means that none of our monomers will be ready in time to polymerize at College of Charleston, which has been the source of some tension. I'm trying to remind myself that, in the real world, there isn't really a time-limit on research - even with the pressure to submit papers for certain journals and symposiums with deadlines - so I shouldn't be worried that three weeks of experimental work didn't yield the results that we had hoped for.
I expect that my group will have its work cut out for us during the upcoming semester.
Monday, January 21, 2013
Day Twelve: Long but Good
Hello, after what I hope was a wonderful weekend!
I suppose that I could document my day's activities. However, there isn't much new information to report. We characterized our Grignard reaction and decided to run it again, keeping me in the lab from 8:50 - 6:30...not the longest day I've spent in a laboratory, but definitely unexpected.
What I'd rather do is reflect on how this day of work affected my attitude toward the future.
There are a lot of cool Interim projects on campus this year: Latin dance, knitting, yoga and rock-climbing. I was recommended to quite a few of these, and would gladly have participated in any of them. After spending my last two Interim terms out of the country - first in Chile, then in Italy - it might have made sense to pick a project that was more relaxing, especially considering that I leave for my semester abroad a week after Interim ends. I knew, though, that this might be my only chance to garner research experience this academic year. Not only that, if I couldn't travel and explore new cultures, I couldn't see myself anywhere other than in a chemistry laboratory.
I won't lie and say that watching a half-hour reflux is the most enjoyable task. It's actually somewhat tedious, all things considered. But I found myself comforted in the knowledge that I could have a reflux running in one hood, a GC sample being scanned in the other lab, and be setting up a new apparatus or washing glassware all at once. I enjoyed wandering back and forth and comparing my reaction process to my lab mates'. In comparison to last week's trial, today's experiment proceeded without a hitch, so it was nice to lean back and observe without significant stress.
Another wonderful aspect about the day was affirming my desire to attend graduate school and being able to hash out my ideas with another chemistry major. As of now, I still don't know where I'm headed, but I am confident that organic chemistry is a viable option for me. I love the work that I've done this Interim and can't wait to pursue chemical research for the next few years!
I suppose that I could document my day's activities. However, there isn't much new information to report. We characterized our Grignard reaction and decided to run it again, keeping me in the lab from 8:50 - 6:30...not the longest day I've spent in a laboratory, but definitely unexpected.
What I'd rather do is reflect on how this day of work affected my attitude toward the future.
There are a lot of cool Interim projects on campus this year: Latin dance, knitting, yoga and rock-climbing. I was recommended to quite a few of these, and would gladly have participated in any of them. After spending my last two Interim terms out of the country - first in Chile, then in Italy - it might have made sense to pick a project that was more relaxing, especially considering that I leave for my semester abroad a week after Interim ends. I knew, though, that this might be my only chance to garner research experience this academic year. Not only that, if I couldn't travel and explore new cultures, I couldn't see myself anywhere other than in a chemistry laboratory.
I won't lie and say that watching a half-hour reflux is the most enjoyable task. It's actually somewhat tedious, all things considered. But I found myself comforted in the knowledge that I could have a reflux running in one hood, a GC sample being scanned in the other lab, and be setting up a new apparatus or washing glassware all at once. I enjoyed wandering back and forth and comparing my reaction process to my lab mates'. In comparison to last week's trial, today's experiment proceeded without a hitch, so it was nice to lean back and observe without significant stress.
Another wonderful aspect about the day was affirming my desire to attend graduate school and being able to hash out my ideas with another chemistry major. As of now, I still don't know where I'm headed, but I am confident that organic chemistry is a viable option for me. I love the work that I've done this Interim and can't wait to pursue chemical research for the next few years!
Friday, January 18, 2013
Day Eleven: Pyrotechnics and Argon
Dawned the morning of our scaled-up Grignard reaction. Fortunately, it was sunny and low in humidity, so keeping moisture out of the lab was a much more feasible goal. However, we still had to dry our glassware prior to starting the reaction, and we wanted to do what we could to maintain the dryness throughout the experimental run.
Enter a hair dryer, a flame torch, and a large tank of argon gas.
Even after removing my glassware from the oven, there was a significant amount of water in my round-bottomed flask. Before assembling my reflux apparatus, I clamped the flask aloft and ran a hair dryer in a swirling motion below it. Once most of the moisture was gone, I added the remaining pieces of glassware and stoppered the ends with dessicant tubes. Then, I ignited a small flame torch and ran it lightly from bottom to top outside the apparatus, watching the condensation move up into the dessicant tubes:
After that, we connected gas tubing where the dessicant tubes had previously been via syringe needles poked through rubber septa. It took some adjusting to infuse all three apparatuses with argon, but it was effective once we got it to work. The problem that arose then was the amount of pressure due to the argon, even with the outlet tube. Since my alkyl halide, benzyl chloride, is quite volatile, the reflux process caused a lot of my reaction solution to spit out of the RB flask instead of condensing and falling back down. We promptly removed the argon and the heat from my apparatus, though, and the rest of the experiment proceeded without any other disruptions.
The product has been left to stir over the weekend and will be characterized and oxidized on Monday!
Enter a hair dryer, a flame torch, and a large tank of argon gas.
Even after removing my glassware from the oven, there was a significant amount of water in my round-bottomed flask. Before assembling my reflux apparatus, I clamped the flask aloft and ran a hair dryer in a swirling motion below it. Once most of the moisture was gone, I added the remaining pieces of glassware and stoppered the ends with dessicant tubes. Then, I ignited a small flame torch and ran it lightly from bottom to top outside the apparatus, watching the condensation move up into the dessicant tubes:
After that, we connected gas tubing where the dessicant tubes had previously been via syringe needles poked through rubber septa. It took some adjusting to infuse all three apparatuses with argon, but it was effective once we got it to work. The problem that arose then was the amount of pressure due to the argon, even with the outlet tube. Since my alkyl halide, benzyl chloride, is quite volatile, the reflux process caused a lot of my reaction solution to spit out of the RB flask instead of condensing and falling back down. We promptly removed the argon and the heat from my apparatus, though, and the rest of the experiment proceeded without any other disruptions.
The product has been left to stir over the weekend and will be characterized and oxidized on Monday!
Thursday, January 17, 2013
Day Ten: Humidity Problems
Very little to report today. With the non-stop rain in upstate South Carolina, lab conditions weren't really optimal for performing another Grignard reaction today. We decided to perform the calculations necessary for a scaled-up experiment (2 mL cyclohexene oxide to 10 mL) and prepare the glassware and reagents to run our reaction tomorrow. Since my compound, benzyl chloride, is volatile, I completed an experiment of Dr. Bass's during normal lab time, which included a GC scan and a simple distillation. After placing our glassware in the oven to dry, we called it a day!
Hopefully there will be more to do and say tomorrow.
Hopefully there will be more to do and say tomorrow.
Subscribe to:
Posts (Atom)