Dimensional Evolution of Polyphenylenes: Expanding in All Directions

Abstract

Polyphenylenes (PPs) represent a class of conjugated polymers that have been used in applications ranging from organic electronic devices, sensors, polymer film additives to manipulate their mechanical properties, and even fluorescent tags or nanocarriers in biological media.1-3 The versatility of PPs stem from innovative synthetic strategies that have evolved throughout the years to provide avenues that precisely tune their architecture and function for specific purposes. This Review will cover the state of the art research on various PPs related to the relationship between their structure and resulting properties.

Application of Rigidity‐Controlled Supramolecular Affinity Materials for the Gravimetric Detection of Hazardous and Illicit Compounds

“…In addition to metal–organic frameworks, representing another important class of materials, established supramolecular hosts are, for example, crown ethers, cyclodextrins, and calixarenes . A particularly intriguing polymeric class for host–guest chemistry with such high porosity, are modified dendritic polyphenylenes (PPDs) . In contrast to other dendrimers consisting of conformational flexible moieties, PPD derivatives exhibit a rigid and persistent shape because only confined rotation around the individual biaryl axis can occur.…”

Ultra‐Narrow Low‐Bandgap Graphene Nanoribbons from Bromoperylenes—Synthesis and Terahertz‐Spectroscopy

“…Our synthesis of GNRs proceeds via non‐planar polyphenylene precursors, which are then “graphitized” by cyclodehydrogenation, leading to defined widths, lengths, and edge structures . Atomically precise GNRs thus emanate from the topologies of 3D polyphenylenes, which in turn can be designed by the choice of the monomeric oligophenyl building blocks and their mode of aryl–aryl coupling . This two‐step protocol can be executed by classical solution chemistry or after deposition of the monomers on metal surfaces .…”

“…[1b] Atomically precise GNRs thus emanate fromt he topologies of 3D polyphenylenes, which in turn can be designed by the choice of the monomeric oligophenyl buildingb locks and their mode of aryl-aryl coupling. [3] This two-step protocol can be executed by classical solution chemistry or after deposition of the monomers on metal surfaces. [1b, 4] Armchair graphene nanoribbons (AGNRs) with widths of N = 13, [5] 9, [4c] 7, [5][6] and 5 [7] (Figure 1a)h ave so far been prepared by solution and surface-mediated methods.…”

“…The published syntheses of soluble 5-AGNR derivatives suffer from poor solubility of the products and incomplete cyclodehydrogenation, leading either to higher rylenes [9,11] (Figure 1b,c ,a nd e) or poly(quaterrylene) [12] (Figure 1d). [13] Cyclodehydrogenation, for example of tert-octyl-phenoxy-solubilized poly(perylene) 1 (see Scheme 1) with iron(III) chloride or iodine, fell short of full ribbon fusion, [12] however the combination of dichlorodicyanoquinone (DDQ)a nd scandiumt riflate (Sc(OTf) 3 )h as recently been demonstrated to achieve higher rylenes beyondq uaterrylene( Figure 1). [11b,c, 14] Thus,o ctarylene dicarboximide, the longest rylene chromophorewith amolecular length of 4nm, could be realized.…”

Sequence-defined oligo(ortho-arylene) foldamers derived from the benzannulation of ortho(arylene ethynylene)s

“…From a structural standpoint, oligo- and polyphenylenes are among the most simple motifs, and high molecular weight poly( p -phenylene)s and poly( m -phenylene)s have been studied extensively. 2 p -Phenylenes have served as precursors to graphene nanoribbons, while m -phenylenes provide improved solubility 3 and have found use in display technologies, including electrophosphorescent devices and liquid crystal displays. 4 …”