.png){kind=icon}
.png){kind=icon}
Return
Sequential Single-Crystal-to-Single-Crystal Transformations Generate Polymer Polymorphs
.png){kind=icon}
PRE
AI
DOI：10.1002/anie.1002118.png)
.png){kind=icon}
Original request for help.png){kind=icon}
Share.png){kind=icon}
Save
Abstract
En 中文
Accessing structurally well-defined polymer polymorphs remains extremely challenging because obtaining polymer single crystals suitable for atomic-level structural characterization is rare. Here we report an unusual sequence of single-crystal transformations in which a peptide monomer designed for topochemical azide–alkyne cycloaddition (TAAC) undergoes spontaneous single-crystal-to-single-crystal (SCSC) polymerization to form a 1,4-triazolyl-linked polymer, despite a crystal packing seemingly predisposed for the formation of a 1,5-linked product. Structural and computational analyses reveal that large-amplitude rotations of the azide and alkyne groups enable the unexpected regioselectivity. Prolonged heating subsequently triggers a rare SCSC polymorphic transition of the polymer crystal, generating a second conformational polymorph with distinct chain packing and mechanical properties. These results demonstrate that sequential single-crystal transformations can provide controlled access to polymer polymorphs from a single monomer crystal.
Keywords:
click chemistry
peptide polymers
polymorphism
single-crystal-to-single-crystal
topochemical reaction
Journal
IF:
16.9
Papers:
4.7K
Citations:
368