Blue fluorescent conductive poly(9,10‐di(1‐naphthalenyl)‐2‐vinylanthracene) homopolymer and its highly soluble copolymers with styrene or 9‐vinylcarbazole

A new blue fluorescent monomer, 9,10‐di(1‐naphthalenyl)‐2‐vinylanthracene, was designed and synthesized in good yield. Its homopolymer poly(9,10‐di(1‐naphthalenyl)‐2‐vinylanthracene) (P( ADN )) and soluble conductive vinyl copolymers poly[(9,10‐di(1‐naphthalenyl)‐2‐vinylanthracene)‐ co ‐styrene] (P( ADN ‐ co ‐S)) and poly[(9,10‐di(1‐naphthalenyl)‐2‐vinylanthracene)‐ co ‐(9‐vinylcarbazole)] (P( ADN ‐ co ‐ VK )) were synthesized using free radical solution polymerization. All the polymers showed high glass transition mid‐point temperatures (203 to 237 °C) and good thermal stabilities. The photoluminescence emission of the copolymers was similar to that of P( ADN ) (with two maxima at 423 and 442 nm). The lifetimes of P( ADN ‐ co ‐S) (6.82 to 7.91 ns) were all slightly less than that of P( ADN ) (8.40 ns). The lifetime of P( ADN ‐ co ‐ VK ) increased from 7.8 to 8.8 ns with an increase in VK content. The fluorescence quantum yields of P( ADN ‐ co ‐S) showed an overall increasing tendency from 0.42 to 0.58. The quantum efficiencies of P( ADN ‐ co ‐ VK ) decreased from 0.36 to 0.19 with an increase of VK fraction. With increasing S/ VK content, the highest occupied molecular orbital of P( ADN ‐ co ‐S)/P( ADN ‐ co ‐ VK ) ranged from −5.58 to −5.73 eV , which was similar to that of P( ADN ) (−5.71 eV ). The band gaps of P( ADN ‐ co ‐S) and P( ADN ‐ co ‐ VK ) were about 2.97 eV , which were equal to that of P( ADN ), and smaller than that of 2‐methyl‐9,10‐di(1‐naphthalenyl)anthracene ( MADN ) (3.04 eV ) and poly(9‐vinylcarbazole) (3.54 eV ). Preliminary electroluminescence results were obtained for a homojunction device with the configuration ITO / MoO 3 (20 nm)/P( ADN )/ LiF (1 nm)/Al (100 nm), which achieved only 30–50 cd m −2 , due to P( ADN ) having a low mobility of 4.7 × 10 −8  cm 2  V −1  s −1 compared to that of its model compound MADN of 6.5 × 10 −4  cm 2  V −1  s −1 . © 2013 Society of Chemical Industry