#ir-spectroscopy

[katesinorganiclabblogthing]

Experiment 38

Organoplatinum complexes made up the last experiment of the semester. This experiment was beneficial to me because I was able to practice both H-NMR and C-NMR after not using either for a while. I liked that I was able to practice NMR because it could be a useful skill to use throughout my career, and it is important that I at least know the basics of how it functions.

I struggled with the synergistic bonding exhibited by the platinum and alkene, but I tried to make it the focus of my report. My report's introduction discussed synergistic bonding (aka backbonding) as well as a brief background on how NMR functions. To support any conclusions drawn from the NMR spectrum, an IR spectrum was also taken.

[katesinorganiclabblogthing]

Experiment 37

Experiment 37 was another synthesis of cis and trans isomers. This week's isomers included cis and trans-dichloro(dipyridine)platinum(II). The image above depicts the symmetries of the isomers and how they vary.

I determined the cis-isomer belonged to the point group C2v, and the trans isomer belonged to D2h. I attempted to highlight the axes and planes of symmetry with ChemDraw so that I could use them to explain my reasoning within my introduction.

I used IR spectroscopy to determine whether the isomers were successfully produced and compared their symmetries to differentiate between the spectra.

[katesinorganiclabblogthing]

MOFs

This experiment synthesizes ZIF-8 and ZIF-67 complexes, both types of metal-organic frameworks (MOFs). Several different types of analyses were run this week to determine whether the experiment was successful.

I studied the particle sizes with SEM, solid-state UV-Vis, magnetic susceptibility, IR, X-ray diffraction, and TGA of the complexes. I have not used X-ray diffraction, solid-state UV-Vis, or SEM before, so I gained a lot from this experience.

I appreciated that I was not only able to practice analyzing the data for these new techniques, but I was also able to run the XRD and observe the solid-state UV-Vis.

[katesinorganiclabblogthing]

Experiment 49

Today I synthesized cis and trans-bis(glycinato)copper(II) monohydrate. This topic allowed me to review the basic topic of thermodynamic and kinetic products, which were first discussed in organic chemistry. 

I tried to focus my lab report on the differences in symmetries (shown in the image above), which determine the point groups and vibrational motions of the complexes. I found it difficult to explain these differences with the IR spectra, but I ended up using the location of the carbonyl peak around 1720 to describe symmetry’s effect on the complexes. 

[katesinorganiclabblogthing]

Experiment 47

Experiment 47 focused on saccharin complexes with cobalt and copper. Product A was tetraaqua-bis(o-sulfobenzoimido)copper (II), and product B was tetraaqua-bis(o-sulfobenzoimido)cobalt(II).

To analyze the product, I used IR, UV-Vis, and TGA. This was my first time using UV-Vis for this lab, although I have experience outside of class. It was interesting to see how different types of spectrophotometers function. I have used a different form of UV-Vis for my organic lab, and another at my internship, so I enjoyed learning about the different software.

After lab, I learned about the process behind writing introductions for lab reports. I typically write my introduction section first, but I have never been taught what exactly I should be discussing. I'm glad I was able to get feedback on what is actually important to an introduction.

[katesinorganiclabblogthing]

Experiment 22

"Today," I synthesized metal acetylacetonates. The expected products were tris(2,4-pentanedionato)chromium(III) and tris(2,4-pentanedionato)manganese(III).

For this experiment, I got to practice calculating the magnetic moment given the magnetic susceptibility. I believe my calculations improved a lot after studying a walk-through of an example magnetic moment calculation.

My yields were overall slightly better than the previous experiment. I had a yield of 23.08% for product A, and 56.61% for product B. I was able to get melting points close to their expected ranges, so the little product synthesized was likely pure.

I was also able to build on my knowledge of IR peak identification for this experiment.

[katesinorganiclabblogthing]

Experiment 20

For the second experiment of the semester, I synthesized metal complexes of dimethyl sulfoxide. There were 3 products: CuCl2*2DMSO, PdCl2*2DMSO, and RuCl2*4DMSO.

Parts A and B only involved stirring the solution before vacuum filtering. Product C involved refluxing the solution before reducing with a stream of gas. After reducing the solution, acetone was added, and the mixture was cooled. Finally, the solution was filtered, and all of it went straight through the filter.

For product A, 55.60% of the expected product was obtained. Product B yielded much less, 7.98% of the expected yield. Product C was not successful; no crystals were collected with vacuum filtration.

While part C was not successful, I learned more about determining the melting point for products A and B. Enough product was made, so I was also able to analyze the IR spectroscopy.