From Distinct Metallopeptoids to Self‐Assembled Supramolecular Architectures
Pritam Ghosh, Natalia Fridman, Galia Maayan
Abstract
Abstract The construction of synthetic protein mimics is a central goal in chemistry. A known approach for achieving this goal is the self‐assembly of synthetic biomimetic sequences into supramolecular structures. Obtaining different 3D structures via a simple sequence modification, however, is still challenging. Herein we present the design and synthesis of biomimetic architectures, via the self‐assembly of distinct copper‐peptoid duplexes. We demonstrate that changing only one non‐coordinating side‐chain within the peptoids—sequence‐specific N‐substituted glycine oligomers—leads to different supramolecular structures. Four peptoid trimers incorporating 2,2’‐bipyridine and pyridine ligands, and a non‐coordinating but rather a structure‐directed bulky group were synthesized, and their solutions were treated with Cu 2+ in a 1:1 ratio. Single‐crystal X‐ray analysis of the products revealed the self‐assembly of each peptoid into a metallopeptoid duplex, followed by the self‐assembly of multiple duplexes and their packing into a three‐dimensional supramolecular architecture via hydrogen bonding and π–π interactions. Tuning the non‐coordinating side‐chain enables to regulate both the final structure being either a tightly packed helical rod or a nano‐channel, and the pore width of the nano‐channels. Importantly, all the metallopeptoids structures are stable in aqueous solution as verified by cryo‐TEM measurements and supported by UV/Vis and EPR spectroscopies and by ESI‐MS analysis. Thus, we could also demonstrate the selective recognition abilities of the nano‐channels towards glycerol.