Catalytic Synthesis and Structural Characterizations of a Highly Crystalline Polyphenylacetylene Nanobelt Array

Abstract

PPA nanobelts were synthesized using nanocopper particles as catalysts in the gas-phase polymerization of phenylacetylene. This route offers several advantages over the conventional method: copper is used instead of expensive noble metal catalysts; gas-phase reaction avoids the use of toxic organic solvents; highly crystalline PPA nanobelt arrays can be produced. PPA nanobelts were characterized by XRD, SEM, TEM, AFM, and DSC techniques. The PPA nanobelts were highly crystalline and have the cis-specific conformation. The I−V characteristics of a single nanobelt with different doped levels were characterized. All three belts show semiconductor features. An undoped PPA belt has the largest insulating gap (about 10 V). Doping the nanobelts with iodine significantly decreases the gap. The belt that underwent 30 min of iodine doping is nearly a conductor.

Self‐Assembly of Functional Molecules into 1D Crystalline Nanostructures

“…Other regioregular poly(3‐alkylthiophene)s such as P3BT, P3PT, and a copolymer of P3PT/P3OT were also reported to self‐assemble into crystalline nanowires with a diameter of 13–16 nm by Jenekhe and co‐workers . Single crystal nanobelt arrays of polyphenylacetylene (PPA), an aryl substituted conjugated polymers with excellent stability in air and multiple applications, were reported by Wang and co‐workers through a gas phase reaction by using the copper nanoparticles as a catalyst . Xia and co‐workers fabricated 1D crystalline nanobelts from the air stable n‐type polymer poly(benzobisimidazobenzophenanthroline) (BBL) by a precisely controlled solution‐phase self‐assembly in methanol or water .…”

Supramolecular Assemblies from Poly(phenylacetylene)s

“…Other one-dimensional nanostructures that resemble nanofibers are nanobelts, and PPAs have also been used as starting polymers to produce that type of aggregate. Thus, Wang, Song, and co-workers developed a protocol to generate a PPA-derived nanobelt . It is based on the polymerization of phenylacetylene monomer in the vapor phase catalyzed by cooper nanoparticles (100 nm).…”

“…(d) TEM study of an individual PPA nanobelt. Reproduced from ref . Copyright 2007 American Chemical Society.…”

Helical nano-structures self-assembled from dimethylaminoethyloxy-containing unsymmetrical octakis-substituted phthalocyanine derivatives

“…Chemical doping is revealed to increase the transistor property of conducting organic semiconductors. 37 Dozens of individual nanostructures of compounds 1 and 2 were prepared to examine their semiconductivity change after being doped with iodine vapor for 15 min. Iodine is a strong oxidative reagent that is capable of obtaining an electron from the nanostructures through a ground-state redox reaction.…”