Patent ID: 7557249

Claim:
A spirobifluorene derivative which has the general formula (IV) and corresponding radical anions: wherein R 5 =A-C═O, and R 4 =R 6 =H; or R 5 =A-C═O and R 4 =R 6 =C 1-4 (alkyl); or R 6 =A-C═O and R 4 =R 5 =H; or R 6 =A-C═O and R 4 =R 5 =C 1-4 (alkyl) A is phenyl, biphenyl, 1-naphthyl, 2-naphthyl, 2-thienyl, 2-furyl, 2-pyrrolyl, 3-thienyl, 3-furyl, 3-pyrrolyl, 9-anthryl, perylenyl, fullerenyl, or a substituted derivative thereof.