The Synthesis Dilemma

I apologize for not posting as much as I probably should, but up to this point, despite a large number of trials and theories, very little overall progress has been made, due to a number of extenuating conditions. Let’s talk.

After the first week of research, I was working with the photobase-generating (PBG) compound that our lab had synthesized in the Spring. However, it gave very strange results when tested in conjunction with nanoparticles (insignificant pH change) and also when tested in solution by itself (upon irradiation, it appeared to release acid instead of base). According to our UV-Vis Spectrophotometer, an instrument that can calculate the concentration of a solution based on its absorbance of a specific wavelengths of light and also give some information on the composition of a compound, the compound had decomposed. An NMR confirmed that there were some impurities, so I began to work to synthesize more.

For the first few weeks of research, I ran the synthesis 6 times, changing various factors and optimizing what I could. However, the UV-Vis always showed that I had a vastly different compound than what I wanted, even though the NMR scans were pretty conclusively saying that I had it. The pH/irradiation tests still gave unexpected results, though, so I continued synthesizing.

When I was close to giving up, we discovered that the lamp in the UV-Vis had degraded over time and was showing incorrect results. Use of the departmental UV-Vis showed that I had been making the product all along! So it was encouraging to know that I hadn’t been messing up the whole time, but I had wasted several weeks just to find that it had been an instrumental error preventing me from moving onward. The problem still remained, however, that my pH tests with the PBG were giving strange results. More to come…