A suite of 3D NMR methods for characterizing complex hydrocarbon structure fragments

A suite of triple resonance 3D NMR experiments is presented for the complete connectivity assignment of the hydrocarbon network in complex macromolecular and supramolecular organic structures. These new 3D NMR methods rely only on the presence of a unique set of (13)C resonances (from (13)C(X)) which are separated from the rest of the (13)C NMR spectrum. These experiments take the advantage of region selective excitation and selective inversion by composite pulses to provide correlations among H(A), (13)C(A); H(B), (13)C(B) and neighboring (13)C(X) resonances along three frequency dimensions. These methods include: gHC(A)C(X), gHC(A)C(X)-HH-TOCSY and gHC(A)C(X)-CC-TOCSY experiments. The utility of this approach is illustrated with spectra of selected structure fragments in poly(ethylene-co-n-butyl acrylate-co-carbon monoxide) (polyEBC) prepared from 1,2,3-(13)C(3)-n-butyl acrylate.