Selective Bond Cleavage in Informational Poly(Alkoxyamine Phosphodiester)s

• Published in: Macromolecular rapid communications. Vol. 41; no. 12; pp. e2000215 - n/a
• Main Authors: Cavallo, Gianni, Clément, Jean‐Louis, Gigmes, Didier, Charles, Laurence, Lutz, Jean‐François
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.06.2020; Wiley-VCH Verlag
• Subjects: Amines - chemistry; Chemical Sciences; Cleavage; digital polymers; information‐containing macromolecules; Ionization; Ions; Mass spectrometry; Mass spectroscopy; Molecular Structure; Nitroxide; Organophosphates - chemistry; Polymers; Polymers - chemistry; Scientific imaging; sequence‐controlled polymers; sequencing; Spectroscopy; tandem mass spectrometry; information-containing macromolecules; tandem mass spectrometry; sequence-controlled polymers; digital polymers; sequencing
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.202000215

The collision‐induced dissociation (CID) of sequence‐defined poly(alkoxyamine phosphodiester)s is studied by electrospray ionization mass spectrometry. These informational polymers are synthesized using three different nitroxide building blocks, namely proxyl‐, SG1‐, and TEMPO‐derivatives. For a polymer containing TEMPO‐ and SG1‐based main chain alkoxyamines, it is found that both types of alkoxyamines break in CID tandem mass spectrometry (MS/MS). However, SG1‐sites are preferentially cleaved and this predominance can be increased by reducing collision energy, even though selective bond fragmentation is not observed. On the other hand, for a polymer containing proxyl‐ and SG1‐alkoxyamines, selective bond cleavage is observed at all studied collision energies. The SG1‐alkoxyamines can be first cleaved in MS/MS conditions and secondly the proxyl‐alkoxyamines in pseudo‐MS3 conditions. These results open up interesting new avenues for the design of readable, erasable or programmable informational polymers. Sequence‐defined poly(alkoxyamine phosphodiester)s, containing both proxyl‐ and SG1‐based alkoxyamines, undergo selective bond cleavage in tandem mass spectrometry (MS/MS). When subjected to an optimal collision energy, SG1‐alkoxyamines break selectively. The proxyl alkoxyamines can be fragmented afterwards in pseudo‐MS3 conditions. This stepwise fragmentation opens up interesting opportunities for controlling the sequencing and degradation of informational copolymers.