Tandem mass spectrometry (MS<sup>2</sup>) derives structural information based on the fragment ions formed from an energetically activated macromolecular ion.  Since cyclic ions require at least two bond cleavages to dissociate, macrocyclic polymers usually lead to different fragmentation patterns and product ion distributions, as compared to their linear analogs.  Similarly, branched and hyperbranched architectures and topologies can be distinguished from each other and from linear isomers by fragments generated at the branching points.  Dissociation at or near the branching sites, which are usually favored due to the release of steric strain and reduction of crowding, lead to fragments that reveal the corresponding branch sizes.  Fragmentation of copolymers depends on the mases and intrinsic reactivities of their comonomers.  Isomeric sequences (such as block vs. tapered or alternating) can be differentiated on the basis of the fragmentation pathways possible within each comonomer unit and the mass-to-charge ratios of the resulting fragments.  Such sequence insight can also be gained for copolymeric macrocycles, as their sequence motifs are generally retained in the ring-opened structures formed during fragmentation.  These MS<sup>2</sup> capabilities will be demonstrated with the sequence and architecture characterization of diverse cyclic, linear, and branched homo- and copolymers.

Tandem mass spectrometry approaches for determining polymer structure, sequence, and topology

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.