Characterization of carbon monoxide centered triads in poly[ethylene-co-(butyl acrylate)-co-(C-13-carbon monoxide)] by isotopic labeling and two-dimensional NMR

摘要

Poly[ethylene-co-(butyl acrylate)-co-(carbon monoxide)] (polyEBC) samples, prepared from C-13-labeled carbon monoxide, were characterized using two dimensional (2D) pulsed field gradient (PFG) 750 MHz NMR spectroscopy. To elucidate the complex mixture of structures present in this terpolymer, 2D H-1/C-13 heteronuclear multiple bond correlation (HMBC) experiments were conducted by selectively exciting the enhanced peaks resulting from C-13-labeling. High resolution 2D NMR combined with C-13-labeling of the polymer greatly simplifies the 2D NMR spectra, selectively enhances the weak peaks from low occurrence C-centered triad structures and aids in their resonance assignments.