Patent ID: 8691120

Claim:
A chromene compound having a skeleton represented by the following formula (2): wherein R 1 is an aryl group or a heteroaryl group, and R 2 is an electron donor group having a Hammett constant σ p of not more than −0.1, R 3 and R 4 are each independently a hydroxyl group, alkyl group, haloalkyl group, cycloalkyl group, alkoxy group, amino group, heterocyclic group having a ring member nitrogen atom and bonded to a benzene ring bonded thereto via the nitrogen atom, cyano group, nitro group, formyl group, hydroxycarbonyl group, alkylcarbonyl group, alkoxycarbonyl group, halogen atom, aralkyl group, aralkoxy group, aryl group or aryloxy group, R 5 and R 6 are each independently an aryl group, heteroaryl group, alkyl group, or a group represented by the following formula (3): wherein R 9 is an aryl group or heteroaryl group, R 10 is a hydrogen atom, alkyl group or halogen atom, and m is an integer of 1 to 3, group represented by the following formula (4): wherein R 11 is an aryl group or heteroaryl group, and n is an integer of 1 to 3, R 5 and R 6 may be bonded together to form an aliphatic hydrocarbon ring together with the carbon atom bonded thereto, R 7 and R 8 are each independently a hydrogen atom, hydroxyl group, alkyl group, haloalkyl group, cycloalkyl group, alkoxy group, amino group, heterocyclic group having a ring member nitrogen atom and bonded to the 13-position carbon atom via the nitrogen atom, cyano group, nitro group, formyl group, hydroxycarbonyl group, alkylcarbonyl group, alkoxycarbonyl group, halogen atom, aralkyl group, aralkoxy group, aryl group or aryloxy group, R 7 and R 8 may be bonded together to form an aliphatic ring having 3 to 20 ring member carbon atoms, condensed polycyclic ring having an aromatic ring or an aromatic hetero ring condensed to the aliphatic ring, hetero ring having 3 to 20 ring member atoms, or condensed polycyclic ring having an aromatic ring or an aromatic hetero ring condensed to the hetero ring, together with the 13-position carbon atom bonded thereto, “a” is an integer of 0 to 2, and b is an integer of 0 to 4, with the proviso that when “a” is 2, two R 3 's may be the same or different and when b is 2 to 4, a plurality of R 4 's may be the same or different.