Matyjaszewski K, Woodworth BE
Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213.
Macromolecules. 1998 Jul 28;31(15):4718-23. doi: 10.1021/ma980473e.
The effects of copper(I) and copper(II) metal centers on the atom transfer radical polymerization (ATRP) of styrene and methyl acrylate were investigated. The free-radical polymerizations were initiated by AIBN in the presence of copper(I) and copper(II) complexes. For methyl acrylate, the rate of the polymerization was reduced in the presence of CuIBr/dNbpy and CuIOTf/dTbpy but was unaffected by the presence of CuII(OTf)2/dTbpy. For styrene, under conditions which yield relatively low molecular weight polymer (16 000), no effect was observed in the presence of CuII(OTf)2/dNbpy; however, under conditions which yield high molecular weight polystyrene (50 000-100 000), the polymerization was limited in the molecular weight attainable and stopped at partial conversion. No effect was observed for the free-radical polymerization of styrene in the presence of copper(I) complexes. These results indicate that control in ATRP does not originate in interactions of growing radicals with copper complexes but in the reversible halogen atom transfer.
研究了铜（I）和铜（II）金属中心对苯乙烯和丙烯酸甲酯原子转移自由基聚合（ATRP）的影响。自由基聚合由偶氮二异丁腈（AIBN）在铜（I）和铜（II）配合物存在下引发。对于丙烯酸甲酯，在CuIBr/dNbpy和CuIOTf/dTbpy存在下聚合速率降低，但在CuII(OTf)2/dTbpy存在下不受影响。对于苯乙烯，在生成相对低分子量聚合物（16000）的条件下，在CuII(OTf)2/dNbpy存在下未观察到影响；然而，在生成高分子量聚苯乙烯（50000 - 100000）的条件下，聚合在可达到的分子量方面受到限制，并在部分转化时停止。在铜（I）配合物存在下，苯乙烯的自由基聚合未观察到影响。这些结果表明，ATRP中的控制并非源于增长自由基与铜配合物的相互作用，而是源于可逆的卤原子转移。
