Force constants and electro-optical parameters (EOPs) of hydrogen-bond
ed associates of N-methylacetamide (NMA) were calculated. Super positi
on of monomer, dimer and trimer spectra enables one to reproduce the e
xperimental data on solutions of NMA in CCl4. Splittings of the IR ban
ds in polyamides may be explained as a result of self-association of m
olecules in the form of open-chain multimers with a sufficiently devel
oped network.