Ladder-type conjugated oligomers prepared by the Scholl oxidative cyclodehydrogenation reaction: synthesis, characterization and application in field effect transistors

Abstract

Two novel well defined ladder-type conjugated oligomers have been successfully designed and synthesized through a solution processing method in an excellent yield. The field effect transistors (FETs) fabricated by these ladder-type oligomers with a nice planar structure exhibit excellent charge carrier mobilities, up to 0.10 cm 2 V À1 s À1 and 0.33 cm 2 V À1 s À1 ; furthermore, the devices can work well with a low gate voltage. The ladder-type oligomers are both converted from two precursor co-oligomers, poly(2,7-(1,2,-diphenylethene)-9,9-dioctylfluorene) (PDPF), via an anhydrous FeCl 3 oxidative cyclodehydrogenation. The pronounced red shift shown in the preliminary photoluminescence spectra and the changes of band gaps measured by electrochemical analysis both testify that the better electronic transmission capacity in the FET performance is due to the expanded molecular chain planarization after the chemical cyclodehydrogenation. Interestingly, the precursor oligomers having a linear-type chain and a zigzag-type chain (L-PDPF and Z-PDPF, respectively) show many characteristic differences in their thermal, optical and electrochemical properties.The differences caused by the different types of main chains demonstrate that the macromolecular configurations have a tremendous impact on the functioning of the oligomers.

Quantitative Construction of C≡C Bond: Renaissance of Reductive Coupling of Benzotribromides Promoted by Cu/Polyamine

“…The resulting product was analyzed by NMR and GC‐MS and its composition can be obtained. NMR spectra of products obtained from different ligands (Figure ) reveals that 9 mol% of 1,2‐diphenylacetylene ( 2 a ), 77 mol% of cis ‐1,2‐dibromostilbene ( 3 a) and 14 mol% of trans ‐1,2‐dibromostilbene ( 4 a) were obtained when PMDETA (N,N,N′,N′′,N′′‐pentamethyldiethylenetriamine) was used as ligand. 2 a (58 mol%) and 3 a (42 mol%) were found when TPMA (tris[(2‐pyridyl)methyl]amine) was used.…”

Recent Advances in the Z/E Isomers of Tetraphenylethene Derivatives: Stereoselective Synthesis, AIE Mechanism, Photophysical Properties, and Application as Chemical Probes

“…In 2015, Huang et al synthesized pure (Z)-/(E)-1,2-diphenylethene from diphenyl acetylene (Figure 18 a). [93] The resultant (Z)-/(E)-BDPE compounds were well-characterized and their stereochemical configurations were confirmedb yu sing single-crystalX -ray diffraction (Figure 18 b). When two 9,9-dioctylfluorene groups were introduced into (Z)-/(E)-BDPE through ar igorous Suzuki reaction, pure (Z)-/(E)-PDPF could be obtained.…”

“…In 2015, Huang et al. synthesized pure ( Z )‐/( E )‐1,2‐diphenylethene from diphenyl acetylene (Figure a) . The resultant ( Z )‐/( E ) ‐ BDPE compounds were well‐characterized and their stereochemical configurations were confirmed by using single‐crystal X‐ray diffraction (Figure b).…”

1,2-Dihaloalkenes in Metal-Catalyzed Reactions

“…Wang and co-workers prepared 96 using a Suzuki reaction between 1,2-dibromostilbene (94) and fluorene-2,7-diylbisboronic esters 95. 41 The Onimura group prepared π-conjugated polymers from 1,2-dihaloalkenes. Starting from 2,3-diiodomaleimide 97 and fluorene derivatives 98, they used a Suzuki coupling promoted polymerization to access polymers 99 (Scheme 27).…”