1H and 13C NMR Assignment of Regioirregular Sequence in Poly((S)-(−)-propylene oxide) Prepared with Organotin-Alkyl Phosphate Condensate by 2D NMR Technique

Abstract

Structures of regioirregular sequence in poly((S)-(−)-propylene oxide) prepared with Bu2SnO-Bu3PO4 (1:2) condensate were investigated extensively using 2D NMR technique. 13C NMR signals of regioirregular enchainment of triad and 1H NMR signals of head-to-tail (H-T), tail-to-tail (T-T), and head-to-head (H-H) were assigned by 2D NMR spectroscopy. Assignments of 13C NMR spectra are scarcely consistent with the assignments from the calculations of chemical shift based on shielding effect or on γ-gauche effect and rotational isomeric model.