Microstructure elucidation of poly(9-ethyl-3-hydroxymethylcarbazolyl methacrylate) using two-dimensional NMR spectroscopy

The configurational assignments of poly(9-ethyl-3-hydroxymethylcarbazolyl methacrylate) prepared by solution polymerization with 2,2′-azobisisobutyronitrile (AIBN) as free radical initiator were studied by combination of one- and two-dimensional NMR spectroscopy. The -OCH2 and -NCH2 carbon resonances were distinguished using Distortionless Enhancement by Polarization Transfer (DEPT) experiments. The configurational assignments for main chain methylene and α-methyl group were done by using 2D HSQC spectroscopy. Various geminal and vicinal couplings within the configurational sequences were assigned with the help of Total Correlation Spectroscopy (TOCSY). Two and three-bond order carbon/proton coupling were observed using Heteronuclear Multiple Bond Correlation (HMBC).