Deciphering the Roles of Stereoregularity in the Helical Assembly of PMMA Inclusion Complexes

High Resolution Image Download MS PowerPoint Slide Living systems rely on the precise primary structures of biomolecules to generate complex architectures such as proteins and DNA. However, perturbations in the primary structure can markedly alter the assembly behavior and biological function. Inspired by nature, this study systematically elucidates how the stereoregularity of synthetic poly(methyl methacrylate) (PMMA) governs the formation of helical inclusion complexes (HICs) with fullerene (C 60 ). High-resolution 1 H NMR analysis reveals that the arrangement of m- and r- diad configurations follows Bernoulli statistics, indicative of a random distribution across the prepared PMMA samples ( r -diad fractions range from 1% to 93%). Moreover, multiscale structural characterization reveals that extended syndiotactic segments enable continuous supramolecular encapsulation of C 60 into one-dimensional arrays, forming long-range ordered cylindrical HICs with enhanced thermal stability. In contrast, m -diads interrupt consecutive syndiotactic sequences, leading to segment-dependent wrapping in which only syndiotactic-rich segments can sustain effective helical encapsulation. Consequently, a slight decrease in r- diad fraction from 93% to 60% results in a sharp reduction in the maximum C 60 encapsulation ratio (E-ratio) from 21 to 4 wt %. These findings establish a clear sequence-assembly relationship that clarifies the role of stereoregularity in directing PMMA-based HICs and provides a molecular design principle for engineering stereoregular polymer hosts and programmable supramolecular architectures.