Polymerization of aromatic nuclei. XVIII. Polymerization of benzene to poly‐p‐phenylene by aluminum chloride–air–water

Abstract

Although the reaction of benzene with aluminum chloride has been quite thoroughly examined by prior investigators, the present report is the first one on formation of poly‐p‐phenylene in this system. Optimum conditions, which gave low yields, involved 7 days at 49–51deg;C. The presence of oxygen (oxidant) and presumably water (cocatalyst) was necessary in order for polymerization to occur. Physical and chemical properties, e.g., behavior toward Br2 and H2O2–CH3CO2H, indicate that the polymer structure is slightly different from that of the material from C6H6–AlCl3–CuCl2. The polymer from C6H6–AlCl3 may possess a lower molecular weight and exhibits a greater degree of structural irregularity in the form of dihydrobenzene, p‐quinoid, or polynuclear regions. In the chemical studies, various compounds were used as models (tetrahydroquaterphenyl, triphenylene, and lower p‐polyphenyls).

Dehydro coupling of aromatic nuclei by catalyst-oxidant systems: poly(p-phenylene)

“…The oligomer exists with a low concentration of radical cations, in stable form, associated with the chains.187 Uptake of bromine and peroxide supports the proposition that small quantities of cyclohexadiene or p-quinoid structures interrupt the normal repeating units, as a consequence of incomplete oxidative rearomatization during polymerization. 70 It is indicative that a greater degree of irregularity pertains when a weak oxidant, such as oxygen, is used in conjunction with A1C13 during the coupling reaction. 70 Alternatively, polynuclear regions may be generated.…”

“…70 It is indicative that a greater degree of irregularity pertains when a weak oxidant, such as oxygen, is used in conjunction with A1C13 during the coupling reaction. 70 Alternatively, polynuclear regions may be generated. For example, when benzene is exposed to AlClg, a plethora of products results, including some in the polynuclear category, such as naphthalene, phenylnaphthalenes, and acenaphthene.189 Because of insolubility and of low hydrogen content in some cases, the question of the presence of cross-links has been raised.…”

“…Structural irregularities, such as p-quinoid or cyclohexadiene units, arising from incomplete oxidation have been invoked to rationalize the reactivity toward bromine and peracid. 70 Certainly, interruption of conjugation could have an influence on the spectral results.…”

Laser desorption/fourier transform mass spectra of poly(phenylene sulfide), polyaniline, poly(vinyl phenol), polypyrene, and related oligomers: Evidence for carbon clusters and feasibility of physical dimension measurement

“…Reaction of benzene with aluminum chloride yields various aliphatic structures that could be susceptible to fragmentation during LD/FT mass spectrometry. 43 The rapid attenuation with acquisition time of peaks from high-mass oligomers of PPP (Fig. 2) indicates that the larger chains are losing coherence faster than smaller ones subsequent to excitation into coherent orbital motion.…”

Συστηματα Ημιαγωγιμων Πολυφαινυλενιων-Ινων Του Ανθρακα:παραγωγη-Δομη- Ιδιοτητες-Κατευθυνσεις Εφαρμογων

“…Το ολιγομερές υπάρχει μαζί με μία χαμηλή συγκέντρωση ριζικών κατιόντων, τα οποία βρίσκονται σε σταθερή μορφή και σχετίζονται με τα μακρομόρια. Η πρόσληψη βρωμίου και υπεροξειδίων δικαιολογεί την άποψη ότι μικρές ποσότητες κυκλοεξαδιενίου ή ρ-κινοειδείς δομές διακόπτουν την κανονική διαδοχή των δομικών μονάδων ως αποτέλεσμα ατελούς οξειδωτικής αρωματοποίησης κατά τη διάρκεια του οξειδωτικού πολυμερισμού (7,154). Είναι ενδεικτικό ότι μεγαλύτερος βαθμός τέτοιων δομικών ατελειών λαμβάνεται κατά τη χρησιμοποίηση οξυγόνου ως οξειδωτικού μέσου μαζί με AICI3 κατά τον οξειδωτικό πολυμερισμό.…”