Synthesis and properties of 2,2'-di(heteroaryl)-9,9'-spirobifluorenes

Abstract

A series of 2,2'-di(heteroaryl)-9,9'-spirobifluorenes were prepared by employing Friedländer reaction of 2,2'- diacetyl-9,9'-spirodifluorene with a series of ortho-aminoarenecarbaldehydes. The compound 2,2'-di(benzo[b]-1,10- phenanthrolin-2-yl)-9,9'-spirofluorene (4e) showed a green light emission at 500 nm upon the excitation of the absorption at 374 nm while 2,2'-di(benzo[h] quinolin-2-yl)-9,9'-spirofluorene (4c), 2,2'-di(1,10-phenanthrolin-2-yl)-9,9'- spirofluorene (4d), 2-(benzo[h]quinolin-2-yl)-2'-(benzo[b]-1,10-phenanthrolin-2- yl)-9,9'-spirofluorene (4g), and 2-(1,10-phenanthrolin- 2-yl)-2'-(benzo[b]-1,10- phenanthrolin-2-yl)-9,9'-spirofluorene (4h) showed emissions at 413, 465, 442, and 442 nm upon excitation of the absorption at 370, 362, 370, and 363 nm, respectively, thus having potential for OLED applications. © 2010 The Chemical Society of Japan.