Mr. Karpe,

By linear polarized IR-spectroscopy in solid-state. These modes are very sensible towards inter/intra molecular interactions, and thus with conventional IR-technique there is a very speculative task a precise assignement. Even using H/D exchange, there is unable to assign accurately the IR-bands to corresponding modes.

Please pay attention to, for example, [Ref. 1], where are shown also representative refs to our papers. We have studied by this method more then 200 oligopeptides, their salts and metal complexes. So that the assignment is precise, furthermore compared with other physical methods.

[Ref. 1] Amino Acids, 2010, 38, 45-50, Spectroscopic and structural elucidation of amino acid derivatives and small, peptides: experimental and theoretical tools

T. Kolev, M. Spiteller, B. Koleva