A method is presented for coupling meso-phenylporphyrins bearing a single pentafluorophenyl ring to thiol substituted molecules. Mild reaction conditions are conducive to the employment of a wide range of thiols including biologically active moieties. Both diphenyl- and tetraphenylporphyrins bearing a variety of different substituents on the non-fluorinated rings have been used to demonstrate the wide applicability of the method. (C) 1999 Elsevier Science Ltd. All rights reserved.