Pressure-Induced Polymerization: Addition and Condensation Reactions

Abstract

Under pressure of 1–100 GPa, unsaturated organic molecules tend to form covalent bond to each other for a negative enthalpy change, which often produces polymeric materials with extended carbon skeleton. The polymerization reactions typically happen in crystal, which promotes the topochemical process. This review summarized the topochemical polymerization processes of several alkynes, aromatics, and alkynylphenyl compounds, including the critical crystal structures before the reaction, bonding process, and the structure of the products. Secondly, this review also summarized the condensation reaction identified in the polymerization process, including the elimination of small molecules such as NH3, etc.

Acetylenedicarboxylate as a linker in the engineering of coordination polymers and metal–organic frameworks: challenges and potential

“…94 4.6 Solid-state polymerization in ADC-based CP and MOFs Unsaturated molecules are amenable to solid-state polymerization (SSP) reactions, whereby the p-component of the multiple-bond opens and forms an extended chain. 140 SSP can be induced photochemically, 141 by high pressure, 142 by ionizing radiation or thermally. 143,144 The polymerization in the solidstate is favored, when the unsaturated moieties in the respective material are correctly oriented to each other with short contacts between them (o4.2 Å).…”

Ordered Van der Waals Hetero-nanoribbon from Pressure-Induced Topochemical Polymerization of Azobenzene

“…23−26 Most PIP reactions proceed via a topochemical route, and the structure of the final product was highly related to the intermolecular conformation of its precursors. 27 That means, the molecular stacking is the key to determine the structure of the synthesized materials. For example, 1,4-diphenyl-1,3-butadiyne (DPB) polymerizes via a dehydro-Diels−Alder route at the closest intermolecular distance d C•••C = 3.2 Å, instead of the common 1,4-addition reaction of diacetylenes due to the long alkyne•••alkyne distance.…”

“…Pressure-induced polymerization (PIP) is a successful method for preparing carbon-based materials with extended structures − and has demonstrated its adaptability in the preparation of graphane, , ultra-thin diamond nanothreads, − nanoribbons, as well as graphite–diamond composites. − Most PIP reactions proceed via a topochemical route, and the structure of the final product was highly related to the intermolecular conformation of its precursors . That means, the molecular stacking is the key to determine the structure of the synthesized materials.…”

A Living Topochemical Ring‐Opening Polymerization of Achiral Amino Acid N‐Carboxy‐Anhydrides in Single Crystals

“…Topochemical polymerizations are attractive and promising methods to generate materials with a high degree of ordering, programmed by the starting arrangement of monomeric units in the crystal's 2D/3D‐space. Nearly exclusively these reactions are based on addition chemistries, such as [2+2] and [4+4] cycloadditions, [1] azide‐alkene/alkyne reactions, [2] Dies‐Alder reactions [1a,3] or the polyaddition‐chemistries of dienes or diynes [4] . Typical triggers for such reactions are light, [5] temperature [4b] or pressure, [3,6] potentially allowing the preparation of polymer single crystals, which cannot be generated by other methods [7] .…”