In a complex macromolecules containing couple of moieties that can perform hydrogen bonds are extremely difficult to detect using conventional spectroscopic techniques. NMR has been widely used but not much information is available through FTIR.
Is there any good paper that discusses the investigation of hydrogen bonding in polymers using FTIR spectroscopy?
After reading few recent researches, I got confused. Here is a set of questions for the August audience:
* How hydrogen bonding changes in region between 1400-1700 cm-1 and 3400-3800 cm-1.
* How the FTIR band assignments of hydrogen bonded water, clustered water and London Dispersion Forces changes in the above two regions?
* Any good FTIR spectroscopy references available to support the hypothesis?
Thanks for your help.
The literature of FTIR detection of hydrogen bonding is very rich, please find below some randomly selected references:
http://pubs.acs.org/doi/abs/10.1021/ed034p304
http://www.chemie.fu-berlin.de/~limbach/denisov/207.pdf
http://iopscience.iop.org/0036-021X/48/12/R05
http://www.pnas.org/content/104/36/14215.abstract
http://www.biophys.uni-frankfurt.de/~bredenbeck/publications/nibbering07.pdf
http://www.hindawi.com/journals/jamp/2012/174236/
You can find much more by Google. FTIR is an important method for detecting H-bonding, but it requires a careful interpretation. Sometimes you need a deconvolution of both the carbonyl and the N-H or O-H vibration bands, which are either broadened in the condensed state or consist of more components. In order to prove that the observed frequency shift is really due to H-bonds you have to study carefully the literature of FTIR or related low molecular analogs or to perform temperature- or concentration dependent studies.
Thanks Gyorgy for the response. I have seen all these papers mentioned by you. I am specifically looking for the changes in the peak assignments as a result of inter/intra molecular interactions. Yes, I have conducted extensive survey but unable find the valid assignments for the region between 1400-1800 cm-1.
Either the papers on HBs are too much fundamental or extremely surficial, mostly mentioning about HBs without any direct evidence. Surprisingly, distinct FTIR peak assignments are extremely rare..
I do not know your polymer. Generally the stronger the hydrogen bond the more redshifted the stretch vibration becomes and the more blue shifted the bend (1400-1800 cm-1) becomes. We looked at inter and intra molecular h-bonding with 2DIR, not sure if that more expensive technique would be helpful to you...
Article Structural classification of the amide I sites of a ß-hairpi...
Please look into papers by Prof. Yukihiro Ozaki and his group at Kwansei Gakuin University, Japan.
Deconvolution of the spectra in the region concerned will give the clear picture of hydrogen bonding with other molecules.Try with this. Will get more information and complex hidden any.
Please look into this reference book by L. J. Bellamy. It explains interpretation and shifts of molecules well. You might find what you are looking for.
http://link.springer.com/book/10.1007%2F978-94-011-6520-4
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