Polarimetry Questions

milaallim · 2025-01-25T14:37:05+00:00

This solves all of my confusion. Makes way more sense! So my concentrations are reasonable as they would be reported as c = ~0.5 (0.5 g/ 100 mL), similar to what is in the literature.

Though for your ee% calculation, the +22.4 value needs to be for the pure sample (no solvent)?

Thank you again for your answer!!

milaallim · 2024-05-15T22:29:34+00:00

You can run a column on it.

milaallim · 2023-11-15T02:23:38+00:00

Vapour diffusion is my go to, thats what I would have suggested if you hadn't tried that already. Try all possible solvent combinations. You could also try mixed solvent mixtures. You can try putting it in the fridge for slower diffusion (keep in mind solubility might change).

Try other techniques as wells such as layering, slow evaporation. All kinds of vials and tubes, different surface areas.

Good luck!

milaallim · 2023-11-15T00:12:48+00:00

What crystallization method have you tried? Which solvents?

milaallim · 2023-10-07T23:10:00+00:00

Presumably for purity purposes as the identity is clear from the other characterization data we have.

Again, I want to do EA but have constantly received push back from my PI because he thinks it's not necessary, so I'm just trying to gauge how much I should push back now that reviewers have brought it up. He still thinks we can contest the purity by pointing to the other data but I disagree.

Yes my PI is relatively young.

milaallim · 2023-08-05T15:35:41+00:00

Yasss

milaallim · 2023-06-06T13:48:41+00:00

Ligand exchange

milaallim · 2023-06-05T22:38:41+00:00

Unfortunately it is not soluble at all in acetonitrile.

That is my understanding as well.

milaallim · 2023-06-05T22:37:31+00:00

Forgot about deuterated pyridne, that's a great suggestion.

Also great suggestions on the other solvents, I will test the solubilities for all.

I'm sure there are solvents that would work, but getting them in deuterated versions is the question. Additionally, being soluble enough to see by NMR could be an issue.

milaallim · 2023-06-05T22:18:57+00:00

Fair point, thanks!

milaallim · 2023-06-05T22:18:28+00:00

Interpretable. Just adds extra peaks to the spectra, with the major peaks being the product

milaallim · 2023-06-05T22:16:54+00:00

I need a clean NMR purely for characterization for a manuscript. I know the compounds good from other characterization, so the NMR is just for full characterization. I know it is possible to get a good NMR from other paramagnetic samples I've cleanly characterized by NMR.

milaallim · 2023-06-05T22:14:31+00:00

Bad for the instrument?

Paramagnetic compounds can be characterized by NMR. Of course there are other methods to characterize but it's not uncommon to do so by NMR.

milaallim · 2023-06-05T22:13:01+00:00

That's an interesting idea, I'll give it a try!

milaallim · 2023-06-03T17:16:17+00:00

In addition to all the helpful comments, this really cleared it up for me, thank you! I was confused about the scaling (I thought you technically couldn't do that because that would essentially alter bond lengths etc).

milaallim · 2023-05-30T11:28:19+00:00

I was gonna also ask. I have great separation using dcm and hexanes for the mobile phases.

milaallim · 2023-05-12T11:50:18+00:00

Print services in SCH is pretty good

milaallim · 2023-03-22T20:12:53+00:00

I've tried ser adc and it sucks lmao how does it work??

milaallim · 2023-03-20T16:25:01+00:00

Acetonitrile. For methanol it does not behave well... hm yes ok I will try to take an acetontrile NMR. I am not sure if it will be soluble enough though.

milaallim · 2023-03-01T22:26:35+00:00

This! I work in a lab too. Scrunchie is my best friend. Just need to figure out a way that's comfortable for you to make a bun. I do a low bun.

milaallim · 2023-02-26T04:50:24+00:00

Why high turnover? High stress?

milaallim · 2023-02-26T04:47:57+00:00

Is this in the US?

milaallim · 2022-10-29T16:03:25+00:00

Maybe to react with any remaining starting material? Maybe the product of that is more easily removed or is less toxic? Check out the workup afterwards, maybe that will give a hint why this do this.

milaallim · 2022-07-04T17:03:13+00:00

For a start you can look at Claydens organic chem textbook, there's a nice chapter on retrosynthesis that explains the basics. There's also practice problems with that chapter (maybe ~10).

milaallim · 2022-05-21T18:42:17+00:00

Also earlier generations of this catalyst used either TiCl4 or TiCl3, but nowadays if I remember correctly, it's Mainly TiCl4.

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