Simple Efficient Synthesis of Strongly Luminescent Polypyrene with Intrinsic Conductivity and High Carbon Yield by Chemical Oxidative Polymerization of Pyrene

Abstract

A wholly aromatic polypyrene was synthesized by direct chemical oxidative polymerization of pyrene with ferric chloride as oxidant in hexane/nitromethane. Successful synthesis of polypyrene was thoroughly confirmed by IR, UV/Vis, 1D (1)H NMR, 2D (1)H-(1)H COSY, 2D (1)H-(13)C HSQC, MALDI-TOF MS, elemental analysis, and X-ray diffraction methods. The results indicated that the polypyrene was formed mainly through dehydro coupling between 2- or 1- and 2'- or 1'-positions on pyrene rings having a degree of polymerization of around 24. The polypyrene was purified and then separated into THF-soluble (ca. 10 %) and THF-insoluble (ca. 90 %) fractions. Compared with insulating pyrene monomer, the polypyrene is a controllably conducting polymer that has low conductivity of 3.4x10(-8) S cm(-1) in its virgin state, moderate conductivity of 2.28x10(-4) S cm(-1) upon iodine doping, but much higher conductivity of up to 81.2 S cm(-1) after the insoluble polypyrene was heated up to 1300 degrees C in nitrogen with a high char yield of 70.6 %. In particular, the soluble polypyrene demonstrates much stronger visible color fluorescence and much lower toxicity than pyrene. The soluble polypyrene would be advantageous for detecting Fe(3+) with almost no interference of other metal ions. The soluble and insoluble polypyrene fractions have potential applications as intrinsically luminescent and highly conducting carbon materials, respectively.

Simple synthesis of conducting poly(2-aminothiazole) with high molecular weight

“…This mechanism is actually quite comparable with that observed on polyaniline (see Scheme 2) [33,34]. In this mechanism, besides the role of oxidant attracting electrons, anhydrous FeCl 3 plays as the Lewis acid interacting with the Lewis base CH 3 NO 2 [23,35], then ionizing the primary -NH 2 of 2AT monomers. This leads to a 2AT + [FeCl 3 /CH 3 NO 2 ] − neutral complex.…”

Enzymatic synthesis of 5-amino quinoline oligomers and evaluation of their free radical scavenging activity

“…The strongest diffraction peaks of AQ and OAQ were observed at the same Bragg angles (25º). This similarity assigned that OAQ consists of AQ repetitive units (26)(27)(28). The oxidation of the other quinoline monomers was studied and the similar diffraction spectra were obtained (8)(9)(10)(11).…”

Interfacial chemical oxidative synthesis of multifunctional polyfluoranthene

“…On the other hand, the contact area at the biphasic interface of C 6 H 14 /CH 3 NO 2 could increase due to faster diffusion and more dramatic thermal motion of the reactants at higher temperature, thus enhancing the interaction of oxidants with monomers. This increase in the yield is opposite to significantly exothermic polymerizations of diaminonaphthalene, 20 and diaminoanthraquinone, 21 but matches the chemical oxidative polymerization of benzene, 22 pyrene, 23 and thiophene 17 because they have similar dehydrogenation activity. However, the PFA in both solvents presents its maximum degree of π-conjugation at 70 °C, indicating that 70 °C is the best temperature to obtain PFA with the longest π-conjugated chains.…”