A study of new manganese complexes as potential driers for alkyd paints

In the search for new autoxidation catalysts, the oxidative crosslinking of ethyl linoleate (EL) has been monitored using time-resolved FT-IR (Fourier transform IR spectroscopy), size-exclusion chromatography and GC/MS (gas chromotography/mass spectroscopy). These methods seem to be quite sensitive to changes in the structure of the catalyst. It has been found that the compound [Mn(acac)(3)] (Hacac = 2,4pentanedione) is an efficient catalyst for the oxidation and the oligornerization of EL, which is proposed to proceed not only via hydroperoxide decomposition, but also through substrate activation. The system [Mn(acac)31 with added bpy (=2,2'-bipyridine) has a very high activity for the oxidation of EL. In situ formation of the species [Mn-II(acaC)(2)(bpy)] and [Mn-III (acaC)(2)(bpy)](+), and the high reactivities of these two species with hydroperoxides and with EL, respectively, are proposed as an explanation for the observed high oxidation rate.