Synthesis and Properties of 2,2′-Di(heteroaryl)-9,9′-spirobifluorenes

Abstract

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.