Owing to its great importance as a structural link in proteins, the NH-CO amide group has been the subject of numerous experimental and theoretical investigations. In contrast, the -NH-COO-carbamate group has been re atively ignored despite its importance in biologically ac ive molecules such as local anaesthetics1–2. U p to now, no experimental studies concerning the proton acceptor ability of carbnmates have appeared in the literature. It must be pointed out however thnt ab initio calculations were carried out for the interaction between simple carbarnates and model molecules such as N- methylacetamide or phenol3. In this work, the complexes between N-methyl methyl-carbamate (MMC) and N,N-dimethyl methylcarbamate (DMMC) and model proton donors (phenol derivatives) are studied by IR or FT-IR spectroscopy