[Vorld]

Hello As part of my high school program, I am required to conduct a research project on Chemistry. I was really looking forward to this as I had many ideas for experimenting with catalysts as well as flocculants. However because of the second wave of the COVID pandemic, I no longer have access to the lab and I have no choice but do my research with pre-existing data from databases.

I am finding it very difficult to come up with a Research Question/Topic that is sufficiently complex that I can try investigating with such data. I have looked at many different databases, for example, https://webbook.nist.gov/chemistry/name-ser/, http://www.chemspider.com/ and https://sdbs.db.aist.go.jp/sdbs/cgi-bin/cre_index.cgi.

One thing I have taken a close look at so far is Spectrometry, mostly because there is a lot of data for it. For example, I have considered investigating the effect of substituent position of Chemical Shift in Proton Nuclear Magnetic Resonance(NMR) Spectra. But after talking to my teacher, I realised this is not a very good topic because NMR data is mostly interpreted with relative position of peaks instead of the absolute chemical shifts.

I have also taken a look at thermodynamic data of different organic compounds, however I feel like often the analysis for these relationships can be very straightforward. It is often just a direct relationship between chain length and boiling point. At most there is a little of complexity with polarity for smaller carboxylic acids and alcohols. I have even explored some polymer databases to see if there's any interesting trends, but I am unable to find much.

I would really appreciate if I could get some suggestions or thoughts on this regard. Thank you in advance!

[Meter]

Maybe look into the theoretical basis of a simple chemical reaction, where you look into HOMO/LUMO and general orbital theory. The SN2 reaction might be a good place to start.

Edit: On second thought, maybe this isn't very fitting if the point of the project is data processing. In that case,  I suggest you look into E1/E2/SN1/SN2 reactions and their reaction kinetics + thermodynamics. It might be a bit beyond the scope of your class, but maybe talk to your teacher about it and he/she can help.

[Corribus]

Thermodynamic data are very easy to mine at the NIST webbook and fairly easy to interpret even for general chemistry level. For instance, combustion enthalpies or phase transition points (boiling point) of hydrocarbons as a function of chain length and branching points, or alcohols as a function of chain length and branching point, etc. You might, as an example, plot combustion enthalpies out for various alkanes, and then also plot on a per-carbon basis, where you can so the terminus effects disappear as the alkane gets larger.

Alternatively you can look at solution enthalpies and entropies for various ions dissolved in water to see what trends emerge as you go down and across the periodic table.

And so on.

There are plenty of spectroscopic data as well, but broad trends may be more difficult to make sense of at the high school level.

The NIST webbook is very reliable for data mining. Even better would be if you can get your hands on a CRC handbook.

[Vorld]

For instance, combustion enthalpies or phase transition points (boiling point) of hydrocarbons as a function of chain length and branching points, or alcohols as a function of chain length and branching point, etc. You might, as an example, plot combustion enthalpies out for various alkanes, and then also plot on a per-carbon basis, where you can so the terminus effects disappear as the alkane gets larger.

Thank you so much for these suggestions! I think the effect of different structural isomers on combustion enthalpies is a pretty interesting. It is interesting how it somehow affects the heat of combustion when I thought it only depended on bond type and amount.

Would it be possible for you to elaborate what terminus effect is please? I tried to look it up but I am not able to understand it.

There are plenty of spectroscopic data as well, but broad trends may be more difficult to make sense of at the high school level.

It is not only allowed, but we are encouraged to explore outside of the high school syllabus, so I do not mind trying to understand some higher level chemistry. In fact, I find it very fun. If it is not too much trouble, would it be possible for you to suggest some data I could look at for spectroscopy? I personally find spectroscopy very interesting because it gives me a tangible way to understand what is happening in the structure of a molecule instead of just taking the word of my textbook.

The NIST webbook is very reliable for data mining. Even better would be if you can get your hands on a CRC handbook.

Thank you so much for this suggestion, I will check with my teacher, my school might be able to provide one. I suspect it will make it easier for me to evaluate uncertainties as well.

[Vorld]

On second thought, maybe this isn't very fitting if the point of the project is data processing. In that case,  I suggest you look into E1/E2/SN1/SN2 reactions and their reaction kinetics + thermodynamics. It might be a bit beyond the scope of your class, but maybe talk to your teacher about it and he/she can help.

Thank you! This is very fascinating. From what I understand there is a lot of scope too. I could consider the effects of bond polarity or size of halide on the rate of reaction or enthalpy of reaction. I could also elaborate on the mechanisms of these reactions while explaining any trends. While thermodynamic data for these reactions might be harder to obtain, if I am able to, there is even more for me to explore. Thank you so much for this suggestion once again, I will have fun learning more about these reactions!

[Corribus]

Would it be possible for you to elaborate what terminus effect is please? I tried to look it up but I am not able to understand it. \

Well, what do you notice about the terminal carbons in an alkane versus ones in the middle? As the chain length in an alkane gets long, do you expect the effects to become more or less important to the thermodynamic behavior of the molecules as a whole?

It is not only allowed, but we are encouraged to explore outside of the high school syllabus, so I do not mind trying to understand some higher level chemistry. In fact, I find it very fun. If it is not too much trouble, would it be possible for you to suggest some data I could look at for spectroscopy? I personally find spectroscopy very interesting because it gives me a tangible way to understand what is happening in the structure of a molecule instead of just taking the word of my textbook.

Sure, no intention to discourage you. Mostly it is just that spectroscopic data can be harder to mine. You have to have a better idea of what you are looking for. That said, if you get stuck feel free to use Chemical Forums as a resource to ask questions.

[Vorld]

Well, what do you notice about the terminal carbons in an alkane versus ones in the middle? As the chain length in an alkane gets long, do you expect the effects to become more or less important to the thermodynamic behavior of the molecules as a whole?

Right, I see what you mean. 3 Hydrogens bonded to a single Carbon at the terminals vs 2 Hydrogens to a Carbon in the middle. The bonding could be different at the terminals and affect the molecule's thermodynamic properties. I guess I expect their effects to reduce over chain length. I will have to take a closer look at some data and see if I can make out relationships, thank you for the explanation!

Sure, no intention to discourage you. Mostly it is just that spectroscopic data can be harder to mine. You have to have a better idea of what you are looking for. That said, if you get stuck feel free to use Chemical Forums as a resource to ask questions.

That makes sense. I do know a couple extensive Spectroscopic databases such as the SDBS (https://sdbs.db.aist.go.jp/sdbs/cgi-bin/direct_frame_top.cgi), and NMRShift (https://nmrshiftdb.nmr.uni-koeln.de/portal/media-type/html/user/anon/page/default.psml/js_pane/P-Search;jsessionid=435AF04F0F8FE19CA6DD0E231640515A), but as you said, there really is a lot to make sense of. I'll try to see if I can narrow my research to any particular type of spectra and quantity to make this easier.

Thank you for taking the time to *delete me*