123200-64-6Relevant articles and documents
Self-Reactions of 1,3-Diphenylpropyl and 1,3,5-Triphenylpentyl Radicals:Models for Termination in Styrene Polymerization
Schreck, Vicki Anne,Serelis, Algirdas K.,Solomon, David H.
, p. 375 - 393 (2007/10/02)
Quantitative determination of the products from thermal decomposition of 1,1',3,3'-tetraphenylazopropane (2) and 1,1',3,3',5,5'-hexaphenylazopentane (5) shows that the respective derived title radicals (1) and (4) undergo self-reactions with a similar preference for combination over disproportionation.The proportion of combination increases from 87 to 93percent (Ec-Ed=9.6+/-1.2kJ mol-1 and ΔSc-ΔSd=43+/-7 JK-1mol-1) for (1), and from 86 to 93percent (Ec-Ed=10.6+/-1.4kJ mol-1 and ΔSc-ΔSd=45+/-6 JK-1mol-1) for (4) over the temperature range 80-161 deg.The relevance of these results to the termination mechanism in the radical polymerization of styrene is discussed.Some minor by-products (28)-(30) which arise by addition of 1,3-diphenylpropyl (1) to 1,3-diphenylpropene (14)/(15) have also been detected.The syntheses of the azo compounds (2) and (5), the former as separate, pure meso- and rac-diastereomers (2m) and (2r), and their various expected decomposition products are described.
