The electrical properties of poly(5,6-dihydroxy-2-cyclohexen-1,4-ylene) derivatives

Abstract

A synthesis of cis-5,6-dihydroxy-l,3-cyclohexadiene diesters was developed, and both the cis and trans derivatives were polymerized by using radical initiators. The structure of the polymer consisted predominantly (85-90%) of 1,4-cyclohexenylene units with a smaller amount of 1,2-repeat unit. Molecular weight data were consistent with considerable chain transfer taking place during the polymerization of certain ester derivatives. High molecular weight material was obtained from the polymerization of the cis-dimethyl carbonate and dipivalate ester derivatives and free-standing films of these materials could be prepared. Pyrolysis of the poly(cts-5,6-dihydroxy-2-cyclohexen-l,4-ylene) derivatives resulted in a largely aromatic polymer which contained blocks of p-phenylenes containing an average of six phenylene units. Pyrolysis of the trans-substituted polymer gave a material with properties that were inconsistent with a p-phenylene polymer. When films prepared from the cis derivatives were heated and then exposed to arsenic pentafluoride, the conductivity of the films was well into the semiconductor range (2 S/cm).

Electroluminescent Conjugated Polymers—Seeing Polymers in a New Light

“…A number of other diesters have been polymerized by the same method (again with 10 ± 15 % of 1,2-linkages in the polymer) and thermally converted to PPP, of which the dimethyl carbonate and dipivaloyl esters yield the polymers with the highest molar masses. [227] Regioregular PPP is accessible through a nickel-catalyzed stereoregular polymerization of 71. Despite the regioregularity and low polydispersity of the resulting polymer 74, there are only limited reports on the electroluminescence of PPP derived from it.…”

Elektrolumineszierende konjugierte Polymere – Polymere erstrahlen in neuem Licht

“…Weitere Diester wurden ebenso polymerisiert (ebenfalls mit 10 ± 15 % 1,2-Verknüpfungen im Polymer) und thermisch in PPP umgewandelt, wobei die höchsten Molmassen der Polymere mit Di(methylcarbonaten) und Dipivaloylestern erzielt wurden. [227] Regioreguläres PPP ist durch eine nickelkatalysierte Polymerisation von 71 zugänglich. Obwohl das resultierende Polymer 74 regioregulär und wenig polydispers ist, ist nur selten über die Elektrolumineszenz von PPP berichtet worden, das daraus erhalten wurde.…”

Electro‐oxidative polymerization of 1,3‐Cyclohexadiene

“…The reference electrode was Ag/AgCl. The design of the electrolysis apparatus has been previously reported [13]. CHD, 0.4 mol/l, and 0.1 mol/l of supporting electrolyte were dissolved in dichloromethane (80 ml) under nitrogen atmosphere at 20°C.…”

“…CHD was unable to be polymerized in basic solvents, such as methanol and dimethylformamide, because a nucleophilic reaction of the solvents preferentially proceeds [13]. On the other hand, electropolymerization of CHD occurs in solvents with low basicity, such as nitromethane and acetonitrile.…”