A new type of ligands based on organic acids, such as acetic acid, iminodiacetic acid, succinic acid and isophthalic acid, has been successfully employed in the iron-mediated atom-transfer radical polymerization (ATRP) of vinyl monomers, such as styrene (St) and methyl methacrylate (MMA). The systems containing different organic acids can react at 250 degreesC to 1300 degreesC in "living"/controlled radical polymerizations giving polymers with narrow molecular weight distributions ((M) over bar (w)/(M) over bar (n) = 1.2-1.5). H-1 NMR spectroscopy has been used to study the structure of the resulting polymers. Block copolymers wen synthesized to confirm the ilivingi nature of the system. The measured molecular weights are close to the calculated values for the polymerization of MMA and are somewhat lower than the theoretical ones for styrsne.