Indole derivatives

An indole derivative represented by the following general formula (1),

• wherein,
• R1 and R2 may be same or different, and are groups selected from the group consisting of an alkyl group having 1 to 6 carbon atoms;
• an alkoxy group having 1 to 6 carbon atoms;
• a halogen atom;
• an aromatic hydrocarbon group;
• an aromatic heterocyclic group;
• a condensed polycyclic aromatic group;
• and a di-substituted amino group which has, as a substituent, an alkyl group with 1 to 6 carbon atoms, an alkenyl group with 1 to 6 carbon atoms, an aralkyl group, an aromatic hydrocarbon group or an aromatic heterocyclic group;
• k is an integer of 0 to 3,
• j is an integer of 0 to 4,
• (when k or j is an integer of not smaller than 2, a plurality of R1s or R2s may be different from each other),
• a ring Z bonded to the indoline ring is a 5- to 8-membered ring having no unsaturated bond in the ring, and may have nitrogen and/or oxygen as ring-constituting atoms,
• X1 is a monovalent group represented by the following general formula (1a),
• —(—CR3═CR4—)m—CR5═CR6R7 (1a)
• wherein,
• m is 0 or 1, and
• R3 to R7 may be same or different, and are hydrogen atoms, alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, aromatic hydrocarbon groups, aromatic heterocyclic groups or condensed polycyclic aromatic groups, R6 and R7 together may form a ring, and when R6 is a hydrogen atom or an alkyl group, R7 is an aromatic hydrocarbon group, an aromatic heterocyclic group or a condensed polycyclic aromatic group, and
• X2 is a monovalent group represented by the following general formula (1b),
• —(—CR8═CR9—)n—CR10═CR11R12 (1b)
• wherein,
• n is 0 or 1, and
• R8 to R12 may be same or different, and are hydrogen atoms, alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, aromatic hydrocarbon groups, aromatic heterocyclic groups or condensed polycyclic aromatic groups, R11 and R12 together may form a ring, and when R11 is a hydrogen atom or an alkyl group, R12 is an aromatic hydrocarbon group, an aromatic heterocyclic group or a condensed polycyclic aromatic group.