Cyclization in hyperbranched polymer syntheses: Characterization by MALDI-TOF mass spectrometry

被引：96

作者：

Gooden, JK ^{[1
]}

Gross, ML ^{[1
]}

Mueller, A ^{[1
]}

Stefanescu, AD ^{[1
]}

Wooley, KL ^{[1
]}

机构：

[1] Washington Univ, Dept Chem, St Louis, MO 63130 USA

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 1998年 / 120卷 / 39期

关键词：

D O I：

10.1021/ja9739547

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (TOF) mass spectrometry allowed direct determination of the extent of macrocycle formation that occurred during the polymerization and copolymerization of A(2)B and A(4)B monomers. Cyclization in hyperbranched pentafluorophenyl-terminated poly(benzyl ether)s was indicated by the presence of ions 20 Da less than the masses of acyclic species, owing to the loss of the HF chain ends during polymerization. This loss occurs by intramolecular nucleophilic aromatic substitution of the benzyl oxide focal point functionality upon a pentafluorophenyl chain end. Homopolymerizations and copolymerization of A(2)B and A(4)B monomers gave cyclic products in all cases, and the extent of cyclization depended on counterion, reaction time, and reaction temperature. In the copolymerization, product distributions revealed that larger proportions of A(2)B repeat units in the product led to increased amounts of cyclic products.

引用

页码：10180 / 10186

页数：7

共 32 条

[1] MASS-SPECTROMETRY OF SYNTHETIC-POLYMERS BY UV MATRIX-ASSISTED LASER DESORPTION IONIZATION [J].