Disulfides chain transfer constants

Nair et al. studied the kinetics of the polymerization of MMA at 60-95 °C using N,1SP-diethyl-NjW-di(hydroxyethyl)thiuram disulfide (30a) as the thermal in-iferter [142]. The dependence of the iniferter concentration on the polymerization rate was examined. The chain transfer constant of the propagating radical of MMA to 30a was determined to be 0.23-0.46 at 60-95 °C, resulting in the activation energy of 37.6 kj/mol for the chain transfer. Other derivatives 30b-30d were also prepared and used to derive telechelic polymers with the terminal phosphorus, amino, and other functional aromatic groups [143-145]. Thermal polymerization was also investigated with the end-functional poly(St) and poly(MMA) which were prepared using the iniferter 13 [146]. 

CO J has been utilized to generate a disulfide radical anion in a synthetically altered human a-haemoglobin chain. The electron of the disulfide radical anion then transfers to the protein heme group at a nominal distance of approximately 12 A with an intramolecular rate constant of 188 23 s at room temperature and pH 7. Similarly, CO J reduces the [Fe(CN)6] " modified [ferricytochrome C551 Ru(III)] with a rate constant of 1.9 x 10 s" to give the stable Fe"Ru" and... 

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