Further Insight into the Detailed Characterization of a Polydisperse Cyclodextrin-Based Polyrotaxane Sample by Electrospray Ionization Mass Spectrometry

An easy and fast approach based on electrospray mass spectrometry (ESI-MS) was developed to provide a detailed characterization of a mixture containing polydisperse cyclodextrin-based polyrotaxane (CD-based PR). Here, method gave access to usual data such the weight-average molecular weight, the number-average molecular weight and the polydispersity index, but also to more specific features as the average number of CDs threaded and the average threading degree. Moreover, the nature and the average number of groups grafted per CD, such as sulfate or silyl groups, can be accurately determinate. This ESI-MS approach advantageously complements the widely used NMR and SEC methods and, thereby, constituting a milestone in the actual MS bottleneck regarding the analysis of polydisperse supramolecular assemblies.