TENG Botao, JIANG Shiyu, LU Jiqing, LAN Youzhao, LIU Ya, ZHENG Shaocheng. ELECTRON AFFINITY METHOD FOR DETERMINING THE ACTIVITY OF MONOMERS IN ANIONIC POLYMERIZATION[J]. Acta Polymerica Sinica, 2007,(12):1183-1186.
TENG Botao, JIANG Shiyu, LU Jiqing, LAN Youzhao, LIU Ya, ZHENG Shaocheng. ELECTRON AFFINITY METHOD FOR DETERMINING THE ACTIVITY OF MONOMERS IN ANIONIC POLYMERIZATION[J]. Acta Polymerica Sinica, 2007,(12):1183-1186.DOI:
The electron affinities(EA) of the vinyl monomers with different substituents were used to determine the anionic polymerization activities of the vinyl monomers.To obtain the theoretical EA data of the vinyl monomers
the Gaussian 03 program based on density functional theory was employed.The geometry of the monomers with different substituents was first optimized by a B3LYP method with 6-31G(d) basis sets
then the electron affinities were calculated at the level of(B3LYP/6-311++G(3df
2p).)It is suggested that the method used to calculate the molecular electron affinity is reliable according to the comparison between the predicted and the experimental EA values.The Mulliken charges of(C)(C) double bonds in different monomers is helpful to determine the reactive sites of the anionic polymerization.The monomers with EA values less than-20 kJ·mol
-1
are mainly conjugated alkenes without polarity
which only react with strong nucleophilic initiators.The EA vaules of the monomers with a relatively strong electron-withdrawing substituent are generally in the ranges of-20~60 kJ·mol
-1
which can be polymerized with the weak nucleophilic.While the EA values of the monomers with two strong electron-withdrawing substituents are generally more than 60 kJ·mol
-1
and the corresponding monomers can react with very mild nucleophiles.Therefore
the EA values of the monomers with different substituents could be used to determine the anionic polymerization activities of the monomers.This conclusion was further validated according to the comparison with the Q-e and σ values.
关键词
负离子聚合单体电子亲和势反应活性密度泛函理论
Keywords
Anionic polymerizationMonomerElectronic affinityReaction activityDensity functional theory