Photochemical synthesis of π-extended ullazine derivatives as new electron donors for efficient conjugated D–A polymers

Abstract

We report the synthesis of π-extended ullazine derivatives annulated with either electron-poor pyridine or electron-rich thiophene units through a metal-free, photochemical cyclodehydrochlorination (CDHC) reaction.

Synthesis and Properties of Conjugated Polymers Based on a Ladderized Anthanthrene Unit

“…M n and M w values of polymers were measured at 110 °C by size exclusion chromatography (polystyrene as the standards) using a high-temperature Varian Polymer Laboratories GPC220 (RI detector) in 1,2,4-trichlorobenzene (TCB) (with 0.0125% BHT w/v) as the eluent at a flow rate of 1 mL min –1 and a sample concentration of 1.0 mg mL –1 in TCB. 35 Absorption and photoluminescence properties of the compounds were measured using a Varian diode-array spectrophotometer (model Cary 500) and Varian Cary Eclipse fluorescence spectrofluorometer, respectively, with a 1 cm path length quartz cells. Cyclic voltammograms were recorded on a potentiostat (Solartron 1287) with platinum electrodes (working and counter electrodes) at a scan rate of 50 mV s –1 and a Ag/Ag + (0.01 M AgNO 3 in MeCN) as the reference electrode in an anhydrous and argon-saturated solution of 0.1 M Bu 4 NBF 4 in MeCN.…”

Emerging Bottom‐Up Strategies for the Synthesis of Graphene Nanoribbons and Related Structures

“…This result exposes as ignificant drawback of the photochemical processes for the synthesis of GNRs and effort will have to be spent to overcome this problem. Nonetheless, the CDHC reaction has been used successfully to prepare electron-rich building blocks for organic electronics [105] and other helical GNRs whose conformation can be tuned by changing the aryl groups local on the edge of the GNRs. [106]…”

Efficient Access to Arylated Aza‐ullazines by Regioselective Functionalization of their Pyridine Ring by H−Li Exchange and Electrophilic Substitution

“…Ullazine is a unique planar nitrogen-containing polycyclic aromatic hydrocarbon (PAH) with 16 π-electron system, which holds great promise in organic functional materials such as polycyclic heteroaromatic arenes, [1,2] dye-sensitized solar cells [3][4][5][6][7] and organic field-effect transistors (OFET). [8][9][10] Ullazine has been first synthesized by Balli and Zeller in 1983.…”