Synthesis, gelation and topochemical polymerization of meta-linked oligophenylenebutadiynylene derivatives

Abstract

Rational design of meta-linked oligophenylbutadiynylene (OPBD) derivatives was conducted in order to gain insight into their gelation properties and reactivity toward topochemical polymerization to yield polydiacetylenes (PDAs). Different structural parameters influencing the gel formation such as the presence of peripheral 2-hydroxyethoxy side chains and the position of amide functionalities, responsible for intermolecular hydrogen bonds, were studied. Topochemical polymerization of butadiyne units contained within the OPBDs was performed and the resulting PDAs were characterized by electron microscopy and spectroscopy.

Topochemical polymerization of unsymmetrical aryldiacetylene supramolecules with nitrophenyl substituents utilizing C–H⋯π interactions

“…Polydiacetylenes (PDAs) are unique conjugated polymers with high crystalline features, which are obtained by the solid-state topochemical polymerization of 1, 3-butadiynes 1 or diacetylene. 2 Moieties linked with diacetylene (DA) are versatile building blocks for the construction of molecular complexes, polymer composites and supramolecular structures, 3,4 which are linear, rigid and conjugated, making them ideal for the placement of metal centers at precise distances from each other. 5 Similarly, diacetylenes have been used to connect various organic functionalities, including the linking of aromatic rings to extended conjugated structures or other structures; 6,7 these conjugated structures have attracted con-siderable attention for various applications.…”

Visible and selective gel assembly via covalent click chemistry

“…[17][18][19][20][21] Though efficient, solvent-free, catalyst-free, regio-and stereospecific, and proximity-driven reactions are accomplished in crystals, 19 similarities in molecular organization between crystallization and gelation have led researchers to exploit gel or xerogel states for topochemical reactions. 22,23 Some chemical reactions with color changes or bubbles are suitable for chemical education as they are visible to the naked eye, such as the Briggs−Rauscher reaction, 24 the Elephant's toothpaste reaction that produces a tower of foam, 25 and the Pharaoh's snake reaction. 26 However, for many reactions, we cannot directly tell with naked eyes whether a reaction occurs or estimate the selectivity and how much of the reaction proceeds at a given time.…”

“…In TAAC, pre‐arranged azides and alkynes undergo 1,3‐dipolar cycloaddition within the crystal lattice to form 1,4‐ or 1,5‐disubstituted 1,2,3‐triazoles 17–21 . Though efficient, solvent‐free, catalyst‐free, regio‐ and stereospecific, and proximity‐driven reactions are accomplished in crystals, 19 similarities in molecular organization between crystallization and gelation have led researchers to exploit gel or xerogel states for topochemical reactions 22,23 …”

Light‐driven topochemical polymerization under organogel conditions of a symmetrical dipeptide–diacetylene system

“…Importantly, the topochemical polymerization of DAs can only take place if these moieties are closely packed . Molecules linked to DA may become versatile building blocks for the construction of supramolecular polymeric structures . These novel structures have attracted considerable attention for various types of applications .…”