[snpd]

In my diploma thesis i stumbled upon a pretty special topic: chiral ir spectroscopy, but without looking at light polarization (like in VCD). I basically created a multivariate model (with PLS) with infrared spectroscopy for the determination of D-Tyrosine and L-Tyrosin content in DL-Tyrosine powders based on the effect of changes in absorption wavenumbers of enantiomers. I found out about this phenomenon for amino acids through the application note of thermo fisher (assets.thermofisher.com/TFS-Assets/CAD/Application-Notes/AN54686-npi-summit-x-chemistry-app-note-en.pdf). I wanted to ask if anyone has experience in this field or can give more detailed information, as i couldn't really find any good literature about this topic (this effect is nowhere covered or mentioned). Even the cited literature in the application note doesn't give any further information than, that this effect is based on "crystal symmetry, geometric parameter distinctions, and hydrogen bonding". This gives some hints, but I'm missing further explanation.

I would be very grateful, if someone could help me

[marquis]

Although the paper is listed as Thermo ,a better description is Nicolet.  This company is a subsidiary of thermo.  The author is also an employee of Nicolet, so you should be able to get a hold of him through Nicolet.  Your best bet is to contact the author. As for the work, they were doing ATR(attenuated total reflectance).  Nothing wrong with that, just not straight IR.  Nicollet is a major leader in IR instruments, by the way. I still need to reread the paper a couple of times to see where he is going. The peaks they are working with are relatively minor, but appear to be quite usable.  Ill keep reading.

[marquis]

The posting for the.paper is now listed as "Mixed vs pure- how FT-IR  can assess enantiomers of amino acid samples". By Jaspreet Singh, Ph.D Application Scientist, Thermo Scientific.  See if that gets you a better copy of the paper.

[marquis]

 Try this: arXiz.org.2409.02641v1 dated 04 Sept 2024.titles "Intrinsic mid-ir chirality and chiral thermal emission twisted bilayers.". By Michael T. Enders et al.The Barcelona Institute of Science and Technology, Spain.

Its not exactly what you are describing, but.looks related.  This is new to me, too.  Still think your best bet is to contact the author.  Good luck.

[marquis]

The different Pharmaceutical companies have been doing chiral HPLC for quite a while. The typical way to do QC was to test the incoming material by chiral HPLC, which can be time consuming and expensive.  It looks like this paper ( the one by thermo scientific) is an alternative to using chiral HPLC as a QA test.  It also looks like a cost savings.  That's a guess, but..