The atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) is often carried out under homogeneous conditions, so the residual metal catalyst in the polymer often influences the quality of the polymer and causes environmental pollution in the long run. Novel CuBr/4,4'-bis(RfCH2OCH2)-2,2'-bpy complexes (R-f = n-C9F19, n-C10F21, or n-C11F23; 2,2'-bpy = 2,2'-bipyridine) are insoluble in toluene at room temperature yet readily dissolve in toluene at elevated temperatures to form homogeneous phases for use as catalysts in the ATRP reaction, and the Cu complexes precipitate again upon cooling. The CuBr/4,4'-bis(n-C9F19 CH2OCH2)-2,2'-bpy system produced the best results (e.g., polydispersity index by gel permeation chromatography = 1.26-1.41), in that the residual Cu content in the polymer was as low as 19.3 ppm when the ATRP of MMA was carried out in the thermomorphic mode. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 110: 2531-2537, 2008