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Determination by 1H and 13C NMR of Stereochemical Compositions of Oligo- and Poly(methyl methacrylate)s Prepared by Group Transfer Polymerization

Oligo- and poly(methyl methacrylate) samples prepared by group transfer polymerization (GTP) in tetrahydrofuran at 0°C with a coinitiator (Me2N)3S+SiMe3F2− were characterized by 1H and 13C NMR spectroscopy and also by 1H-1H and 1H-13C two dimensional (2D) NMR correlation spectroscopy (COSY). The results showed that the values of the fraction fr of racemo dyads were substantially constant (0.79±0.01) irrespective of molecular weight down to the trimer. The distributions of triads in the samples were found to obey Bernoullian statistics, indicating that the racemo and meso dyads were randomly distributed in the oligomer and polymer chains.