In the present work we investigated the conformations of some N-mono-substituted propanamides of general formula CH3CH2CONHR, wherein R is chosen from n-(C1 C9) alkyl, cyclo (C3 C6) alkyl, some branched (C3 C6) alkyl or phenyl. The amides were synthesised by the well known Schotten-Baumann reaction—acylation of the corresponding amines with propionyl chloride. On the basis of FTIR data for diluted solutions ( ...