Biscarbazole derivatives and organic electroluminescence device employing the same

A biscarbazole derivative, which is represented by the following formula (1):

• in the formula (1):
• A1 and A2 each independently represent a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 2 to 30 ring carbon atoms;
• Y1 to Y16 each independently represent C(R) or a nitrogen atom, and R's each independently represent a hydrogen atom, a substituent, or a bond to a carbazole skeleton;
• and
• L1 and L2 each independently represent a single bond, a substituted or unsubstituted, divalent aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted, divalent aromatic heterocyclic group having 2 to 30 ring carbon atoms,
• provided that:
• at least one of A1 and A2 represents a substituted or unsubstituted benzofuranyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted benzothiophenyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted benzonaphthofuranyl group, or a substituted or unsubstituted benzonaphthothiophenyl group;
• when one of A1 and A2 represents a dibenzofuranyl group or a dibenzothiophenyl group, the other represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted benzofuranyl group, a substituted or unsubstituted benzothiophenyl group, a substituted or unsubstituted benzonaphthofuranyl group, or a substituted or unsubstituted benzonaphthothiophenyl group;
• and
• when Y6 and Y11 are bonded to each other, the following conditions (i) and (ii) are satisfied:
• (i) when A1 represents a dibenzofuranyl group or a dibenzothiophenyl group, L1 represents a substituted or unsubstituted, divalent aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted, divalent aromatic heterocyclic group having 2 to 30 ring carbon atoms;
• and
• (ii) when A2 represents a dibenzofuranyl group or a dibenzothiophenyl group, L2 represents a substituted or unsubstituted, divalent aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted, divalent aromatic heterocyclic group having 2 to 30 ring carbon atoms.