Elucidating the Supramolecular Copolymerization of N‐ and C‐Centered Benzene‐1,3,5‐Tricarboxamides: The Role of Parallel and Antiparallel Packing of Amide Groups in the Copolymer Microstructure

Abstract

An in-depth study of the supramolecular copolymerization behavior of N-and C-centered benzene-1,3,5tricarboxamides (N-and C-BTAs) has been conducted in methylcyclohexane and in the solid state. The connectivity of the amide groups in the BTAs differs, and mixing N-and C-BTAs results in supramolecular copolymers with a blocky microstructure in solution. The blocky microstructure results from the formation of weaker and less organized, antiparallel hydrogen bonds between N-and C-BTAs. In methylcyclohexane, the helical threefold hydrogen-bonding network present in C-and N-BTAs is retained in the mixtures. In the solid state, in contrast, the hydrogen bonds of pure BTAs as well as their mixtures organize in a sheet-like pattern, and in the mixtures long-range order is lost. Drop-casting to kinetically trap the solution microstructures shows that C-BTAs retain the helical hydrogen bonds, but N-BTAs immediately adopt the sheet-like pattern, a direct consequence of the lower stabilization energy of the helical hydrogen bonds. In the copolymers, the stability of the helical aggregates depends on the copolymer composition, and helical aggregates are only preserved when a high amount of C-BTAs is present. The method outlined here is generally applicable to elucidate the copolymerization behavior of supramolecular monomers both in solution as well as in the solid state.

Supramolecular Block Copolymers from Tricarboxamides. Biasing Co‐assembly by the Incorporation of Pyridine Rings

“…ΔG A‐B allows the calculation of the parameter R= 1.05, which is close to the unity. This result implies a statistical distribution of the monomeric species exhibiting homo‐ and heterointeractions along the polymeric chain growth to form poly‐1‐co‐4 [3,12b] …”

Supramolecular copolymerization of hydrophobic and hydrophilic monomers in liquid crystalline media

“…44 In the previous examples, the formation of supramolecular block copolymers is governed by the balance between the association energies between the monomers (homo-and heterointeractions). [30][31][32][33][34] In the present case, compatibilizing 5OCB seems to contribute to controlling this energy balance to realize a block sequence with the two monomers, which otherwise undergo self-sorting supramolecular polymerization.…”

Nanoscale assembly of enantiomeric supramolecular gels driven by the nature of solvents

“…For example, polar solvents compete with polar moieties in the gelator, causing the binding strength of the gelator to decrease. 40 The C 3 -symmetric supramolecular platform benzene-1,3,5tricarboxamide (BTA) [41][42][43][44][45] has been thoroughly studied for its tendency to form nanofibers leading to gelation in a wide range of solvents, [46][47][48][49] which is ideal for studying the effect of solvent polarity on the self-assembly process. We have therefore chosen to explore the gelation properties of amino acid derived BTA in various solvents.…”