Über polyenarylene und polyenheteroarylene. 1. Mitt.: Poly‐[thienylen‐(2.5)‐äthenamer] und einige seiner oligomeren. Synthesen, spektrales verhalten und elektrische leitfähigkeit

Abstract

ZUSAMMENFASSUNG:Bei der WITTIG-Reaktion von 2.5-Bis-(triphenylphosphoniomethyl)-thiophen-dichlorid mit Thiophen-2.5-dialdehyd wurde Poly-[thienylen-(2.5)-athenamer] mit endstandigen Aldehydgruppen erhalten. Durch Reaktion mit 2-(Tripheny1phosphoniomethyl)-thiophenchlorid laBt sich ein Teil der Aldehydgruppen in Thieny1-(2)-vinyLGruppen iiberfuhren.Zum Vergleich wurden -ebenfalls rnit Hilfe der WITTIG-Reaktion -Oligomere der allge- (2)-; -R-= Thienylen-(2.5)-] mit n = 1, 2, 3,4, 6 hergestellt. Die Struktur der untersuchten Verbindungen wurde durch UV-Spektren, sichtbare Spektren, IR-Spektren und Massenspektren bestatigt. Zur weiteren Charakterisierung wurden Rontgenuntersuchungen herangezogen. Die Oligomeren sowie das Polymere wurden auf ihre elektrische Leitfahigkeit hin untersucht. SUMMARY:Poly[thienylene-(2.5)-ethenamer] was prepared from 2.5-bis(triphenylphosphoniomethy1)thiophene dichloride and thiophene-(2.5)-dicarbaldehyde via the WITTIG reaction. This polymer has terminal aldehyde groups, which can be reacted partly with 2-(triphenylphosphoniomethy1)thiophene chloride to give terminal thienyl-(2)-vinyl groups. For comparison, there were synthesized via the WITTIG reaction oligomers of the general formula R-(-CH=CH-R-)D-H [-R = thienyl-(2)-; -R-= thienylene-(2.5)-] with n = 1, 2. 3, 4, 6. The structure of the oligomers and the polymer was confirmed by their UV,

Polyarylenealkenylenes and Polyheteroarylenealkenylenes XVIII. Polycondensation of 5-Methylfuran-2-carbaldehyde— An Easy Route to Electrically Conductive Materials

“…The values of the electrical conductivity of 1 is comparable to the values given for pristine poly(2,5-thiophenediylvinylene) 7 with CT 298 K = 3.8x 10-8 Scm-1 and for polyacetylene with 10-8 Scm-1 .…”

Conformational Relaxation of p‐Phenylenevinylene Trimers in Solution Studied by Picosecond Time‐Resolved Fluorescence

“…The presence of vinylene bonds in cis conformation was also tested by refluxing MBOPV3 with iodine in dichloromethane to promote the cis to trans isomerisation. [11] Fluorescence decays of the treated MBOPV3 still showed the presence of the intermediate component and were identical to those of the non-treated MBOPV3. However, the possibility of photoisomerisation during the measurements, does not allow discarding cis isomers as responsible for this residual intermediate component.…”

Synthetic Principles for Bandgap Control in Linear π-Conjugated Systems

“…PPVs were initially prepared by means of the polymerization of bis-[(halomethyl)benzenes] 220 by Wittig olefination 207,221,222 or Knoevenagel condensation. 206 However, these various routes gave essentially low molecular weight insoluble and infusible materials.…”