Effect of H-Bonding on Order Amplification in the Growth of a Supramolecular Polymer in Water

Abstract

While a great deal of knowledge on the roles of hydrogen bonding and hydrophobicity in proteins have resulted in the creation of rationally designed and functional peptidic structures, the roles of these forces on purely synthetic supramolecular architectures in water have proven difficult to ascertain. Focusing on a 1,3,5-benzenetricarboxamide (BTA) based supramolecular polymer, we have designed a molecular modeling strategy to dissect the energetic contributions involved in the self-assembly (electrostatic, hydrophobic, etc.) upon growth of both ordered BTA stacks and random BTA aggregates. Utilizing this set of simulations, we have unraveled the cooperative mechanism for polymer growth, where a critical size must be reached in the aggregates before emergence and amplification of order into the experimentally observed fibers. Furthermore, we have found that the formation of ordered fibers is favored over disordered aggregates solely on the base of electrostatic interactions. Detailed analysis of the simulation data suggests that H-bonding is a major source of this stabilization energy. Experimental and computational comparison with a newly synthesized 1,3,5-benzenetricarboxyester (BTE) derivative, lacking the ability to form the H-bonding network, demonstrated that this BTE variant is also capable of fiber formation, albeit at a reduced persistence length. This work provides unambiguous ev-idence for the key 1D driving force of hydrogen bonding in enhancing the persistency of monomer stacking and amplifying the lev-el of order into the growing supramolecular polymer in water. Our computational approach provides an important relationship di-rectly linking the structure of the monomer to the structure and properties of the supramolecular polymer.

Into the Dynamics of a Supramolecular Polymer at Submolecular Resolution

“…3a: GC monomer ( 1 )) 25, 30, 31 . Our simulations demonstrated that these stacks are not perfect in water, where fibre folding due to hydrophobic effects produces multiple defects/breakages along the supramolecular polymers (Fig.…”

Synthesis, resolution, and chiroptical properties of hemicryptophane cage controlling the chirality of propeller arrangement of a C3 triamide unit

“…13 Besides their use as enantioselective receptors for carbohy-the chirality of the arrangement of the linkers, but also that of the south unit, in particular that of a benzene-1,3,5tricarboxamide (BTA) moiety ubiquitous in supramolecular chemistry. [19][20][21][22][23][24][25][26][27] Herein, we report the synthesis of the new hemicryptophane cage 1. The resolution of the racemic mixture was performed by chiral high-performance liquid chromatography (HPLC), and the assignment of the absolute configuration of the two enantiomers was achieved from electronic circular dichroism (ECD) spectra.…”

Supramolecular Copolymerization as a Strategy to Control the Stability of Self‐Assembled Nanofibers

“…For details of the method, the reader is referred to the Supporting Information. [17,29,31,32] Higher g(c) peaks (relative probability for finding cores at stacking distance c = 3.4 from the neighbors) indicate higher persistence/regularity of the stacking. [17,29,31,32] Higher g(c) peaks (relative probability for finding cores at stacking distance c = 3.4 from the neighbors) indicate higher persistence/regularity of the stacking.…”

“…[17,29,31,32] Higher g(c) peaks (relative probability for finding cores at stacking distance c = 3.4 from the neighbors) indicate higher persistence/regularity of the stacking. [29,31] Ah igher persistence/order (ca. [29,31] Ah igher persistence/order (ca.…”